Too intense training without recovery

Molecular mechanisms of exercise contributing to tissue regeneration

Type of study:

Number of citations: 74

Year: 2022

Authors: Jibao Chen, Ren Zhou, Ye Feng, Lin Cheng

Journal: Signal Transduction and Targeted Therapy

Journal ranking: Q1

Key takeaways: Exercise promotes tissue regeneration in various organs, potentially aiding in the development of therapeutic exercise mimetics for diseases like metabolic and neurodegenerative disorders.

Comparative analysis of high-intensity interval training and traditional rehabilitation programs for accelerated recovery from musculoskeletal injuries

Type of study: rct

Number of citations: 0

Year: 2023

Authors: K. M., Snigdha Josyula, Jenifer Augustina S, Naveen M, H. J., V. J, Karthikeyan P, J. Alagesan

Journal: Journal of Back and Musculoskeletal Rehabilitation

Journal ranking: Q2

Key takeaways: HIIT is more effective than traditional rehabilitation in accelerating recovery from musculoskeletal injuries, with greater pain reduction and improved functional outcomes.

Abstract: BACKGROUND: Musculoskeletal injuries, such as strains, are prevalent across all age groups and have a substantial impact on daily functioning and quality of life. OBJECTIVE: To examine the effectiveness of high-intensity interval training (HIIT) with traditional rehabilitation programs on pain, range of motion (ROM), muscular strength, and functional changes in promoting accelerated recovery from musculoskeletal injuries. METHODS: A total of 80 participants (54 males, 26 females; mean age 35.6 years) with various musculoskeletal injuries were randomly assigned to either the HIIT group ( n = 40) or the traditional rehabilitation group ( n = 40). The HIIT group underwent a six-week supervised program, with three sessions per week. The traditional rehabilitation group followed a similar six-week program emphasizing low to moderate intensity exercises and traditional rehabilitation techniques. Outcome measures, including pain levels, ROM, muscular strength, and functional outcomes, were assessed pre- and post-intervention. RESULTS: Significant improvements were observed in both the HIIT and traditional rehabilitation groups. However, the HIIT group demonstrated superior outcomes. Participants in the HIIT group experienced a greater reduction in pain levels compared to the traditional rehabilitation group (mean visual analog scale (VAS) score decrease of 5.2 vs. 3.8, respectively, p < 0.05). Functional outcomes significantly favored the HIIT group, with participants achieving faster completion times in the Timed Up and Go test (mean reduction of 2.1 seconds vs. 1.5 seconds, respectively, p < 0.01) and longer distances in the Single Leg Hop test (mean increase of 32 cm vs. 25 cm, respectively, p < 0.05). CONCLUSION: HIIT showed superior effectiveness over traditional rehabilitation in accelerating recovery from musculoskeletal injuries, with greater pain reduction and improved functional outcomes. Incorporating HIIT into rehabilitation protocols may offer an efficient approach for expedited recovery and enhanced functional capacity.

Clinical Uses Of Long-Duration Ultrasound And Long-Duration Sonophoresis In Sports Medicine - Minireview

Type of study: literature review

Number of citations: 0

Year: 2025

Authors: Rod Walters, David Snyder

Journal: Journal of orthopaedics (Chesterton, Ind.)

Journal ranking: Q2

Key takeaways: Long-duration ultrasound therapy shows promise in regulating inflammation, accelerating healing, and improving recovery outcomes in sports medicine.

Abstract: Competitive physical sports demand rigorous training, increasing the risk of overuse-associated musculoskeletal traumatic injuries followed by a complex and time-consuming healing process with economic effects and potential disability. Tissue healing involves inflammation, molecular and cellular pathway regulation, proliferation, and tissue regeneration. These responses can significantly vary depending on the location and severity of the injury, affecting recovery time, pain intensity, range of motion, and return to sports activity. Despite medical advancements, healing, pain alleviation, regenerative tissue quality, mobility, and quality of life remain challenging. Current treatments, including nonsteroidal anti-inflammatory drugs and opioid-based treatments, have systemic adverse effects and efficacy limitations. Long-duration ultrasound therapy has emerged as a promising mechanobiological and diathermic treatment, providing critical biomechanical and thermal stimuli. Biomechanical stimuli help regulate acute inflammation, cellular proliferation, and tissue regeneration. Thermal stimuli enhance blood flow, angiogenesis, and nutrient exchange, accelerating healing and improving recovery outcomes. These combined stimuli also increase skin porosity and permeability, facilitating targeted drug delivery through sonoporation and enhancing the efficacy of treatments like platelet-rich plasma therapy. This review examines recent studies exploring the therapeutic effects of long-duration ultrasound as a standalone and adjunctive therapy. It examined its roles in regulating acute inflammation, mitigating chronic inflammation, tissue regeneration, healing, sports-associated pain management, mobility, and overall tissue recovery. KeyWords: Sports Medicine, Long-Duration Ultrasound, Musculoskeletal pain, Sonoporation, Platelet-rich Plasma.

Low-intensity pulsed ultrasound promotes skeletal muscle regeneration via modulating the inflammatory immune microenvironment

Type of study: non-rct experimental

Number of citations: 38

Year: 2023

Authors: Haocheng Qin, Zhiwen Luo, Yaying Sun, Zhong-qin He, Beijie Qi, Yisheng Chen, Junlong Wang, Ce Li, Weiwei Lin, Zhihua Han, Yulian Zhu

Journal: International Journal of Biological Sciences

Journal ranking: Q1

Key takeaways: Low-intensity pulsed ultrasound (LIPUS) at 60mW/cm2 significantly promotes skeletal muscle regeneration by shifting macrophage phenotype from M1 to M2, potentially benefiting clinical treatment of injuries and inflammatory diseases.

Abstract: Background: Low-intensity pulsed ultrasound (LIPUS, a form of mechanical stimulation) can promote skeletal muscle functional repair, but a lack of mechanistic understanding of its relationship and tissue regeneration limits progress in this field. We investigated the hypothesis that specific energy levels of LIPUS mediates skeletal muscle regeneration by modulating the inflammatory microenvironment. Methods: To address these gaps, LIPUS irritation was applied in vivo for 5 min at two different intensities (30mW/cm2 and 60mW/cm2) in next 7 consecutive days, and the treatment begun at 24h after air drop-induced contusion injury. In vitro experiments, LIPUS irritation was applied at three different intensities (30mW/cm2, 45mW/cm2, and 60mW/cm2) for 2 times 24h after introduction of LPS in RAW264.7. Then, we comprehensively assessed the functional and histological parameters of skeletal muscle injury in mice and the phenotype shifting in macrophages through molecular biological methods and immunofluorescence analysis both in vivo and in vitro. Results: We reported that LIPUS therapy at intensity of 60mW/cm2 exhibited the most significant differences in functional recovery of contusion-injured muscle in mice. The comprehensive functional tests and histological analysis in vivo indirectly and directly proved the effectiveness of LIPUS for muscle recovery. Through biological methods and immunofluorescence analysis both in vivo and in vitro, we found that this improvement was attributable in part to the clearance of M1 macrophages populations and the increase in M2 subtypes with the change of macrophage-mediated factors. Depletion of macrophages in vivo eliminated the therapeutic effects of LIPUS, indicating that improvement in muscle function was the result of M2-shifted macrophage polarization. Moreover, the M2-inducing effects of LIPUS were proved partially through the WNT pathway by upregulating FZD5 expression and enhancing β-catenin nuclear translocation in macrophages both in vitro and in vivo. The inhibition and augment of WNT pathway in vitro further verified our results. Conclusion: LIPUS at intensity of 60mW/cm2 could significantly promoted skeletal muscle regeneration through shifting macrophage phenotype from M1 to M2. The ability of LIPUS to direct macrophage polarization may be a beneficial target in the clinical treatment of many injuries and inflammatory diseases.

The effects of training, immobilization and remobilization on musculoskeletal tissue

Type of study:

Number of citations: 81

Year: 1992

Authors: P. Kannus, L. Józsa, P. Renström, M. Järvinen, M. Kvist, M. Lehto, P. Oja, I. Vuori

Journal: Scandinavian Journal of Medicine & Science in Sports

Journal ranking: Q1

Key takeaways: Remobilization can improve muscle function and prevent atrophy, but proper techniques are needed to prevent osteoporosis and maintain bone health.

Abstract: Compared with the knowledge on immobilization, the effects of remobilization on musculoskeletal tissues have not been well established. What is sure is that remobilization and rehabilitation of any component of the musculoskeletal tissues require much more time than the time needed to cause the immobilization atrophy. With intensive rehabilitation, the functional properties of skeletal muscles can be improved significantly even years after the injury and following immobilization, but no study has shown whether full recovery is possible and whether these rehabilitated muscles are able to respond normally to further training. Experimental studies have given evidence that slow‐twitch muscle fibres have better capacity for recovery than fast‐twitch fibres, most likely due to better circulation and higher protein turnover. Also evidence has been given that fibre regeneration is possible through satellite cell activation and myotube formation. Very little is known, however, about the effects of age, gender or the level of preimmobilization muscle performance on the restoration capacity. Also the fate of the marked structural changes (for example, connective tissue accumulation) induced by immobilization is unknown. Tendon and ligament tissues are likely to respond appropriately to remobilization, resulting in acceleration of collagen synthesis and fibril neoformation. However, there is a strong suspicion that remobilized tendons and ligaments will not achieve all the biochemical and biomechanical properties of their healthy counterparts. Specifically, the amount of weak type III collagen has been shown to be overrepresented in these tissues instead of mature, strong type I collagen. It is not known whether this is an important risk factor for ruptures during later activity. The effects of remobilization on muscle‐tendon junction and proprioceptive organs are not known. It would not be surprising if the serious structural changes induced by immobilization were unrestorable. In the literature dealing with immobilization and remobilization, cartilage degeneration is always a major concern, because not only too strenuous training or immobilization, but also unskilful remobilization may activate this process leading finally to osteoarthrosis. Bone may be one of the best components of musculoskeletal tissues to respond to remobilization, probably because the immobilization atrophy of bone is largely quantitative (osteoporosis) only. The prerequisites for bony recovery are that the follow‐up time is long enough (months) and that immobilization has not exceeded about 6 months, the time limit between active and inactive (irreversible) osteoporosis. Prevention of the atrophying effects of immobilization can be very successful if performed properly. According to present knowledge, there are many methods for the purpose, including preimmobilization training early, controlled mobilization; optimal positioning of the immobilized joint; muscular training during immobilization; early weightbearing; exercise with the nonimmobilized extremity; and electrical stimulation. Lots of education and information will be needed, however, before these methods are deeply rooted in the daily routines of the attending physicians, physical therapists, athletic trainers and other persons involved in the treatment of musculoskeletal problems.

The Impact of a Sauna on Post-Exercise Recovery

Type of study:

Number of citations: 0

Year: 2025

Authors: Filip Dębicki, Łukasz Grądalski, Szymon Niemirka, Aleksandra Janiak, Kinga Dominiczak, Adrianna Kopaczyńska, Katarzyna Szafrańska

Journal: Quality in Sport

Journal ranking: brak

Key takeaways: Saunas aid in post-exercise recovery, accelerating tissue regeneration and promoting better performance in athletes by promoting relaxation and calmness.

Abstract: Regeneration of the body after intense exercise is a key element necessary for the proper process of improving performance and achieving better results in strength training.  One of the most important issues in any athlete is the uninterrupted continuation of training and the most optimal regeneration of tissues and the body, which is essential for further improvement of skills and development in a given sport. There are a number of methods to support the repair processes of tissues and help the body fight injuries and micro-injuries that occur during exercise and are an indispensable part of building strength and muscle mass. An example that has recently become very popular in the sports environment is the use of saunas characterized by thermal properties, through which it is possible to influence physiological processes that accelerate the return to form and achieve better results in sports competitions. This form not only helps tissue regeneration, but also relaxes and calms the body, which is stimulated during sports and requires calming afterwards.

The therapeutic effects of low-intensity pulsed ultrasound in musculoskeletal soft tissue injuries: Focusing on the molecular mechanism

Type of study: literature review

Number of citations: 20

Year: 2022

Authors: Haocheng Qin, Liang Du, Zhiwen Luo, Zhong-qin He, Qing Wang, Shiyi Chen, Yu-Lian Zhu

Journal: Frontiers in Bioengineering and Biotechnology

Journal ranking: Q1

Key takeaways: Low-intensity pulsed ultrasound (LIPUS) promotes tissue regeneration in musculoskeletal soft tissue injuries, with its molecular mechanisms largely unexplored.

Abstract: Musculoskeletal soft tissue injuries are very common and usually occur during both sporting and everyday activities. The intervention of adjuvant therapies to promote tissue regeneration is of great importance to improving people’s quality of life and extending their productive lives. Though many studies have focused on the positive results and effectiveness of the LIPUS on soft tissue, the molecular mechanisms standing behind LIPUS effects are much less explored and reported, especially the intracellular signaling pathways. We incorporated all research on LIPUS in soft tissue diseases since 2005 and summarized studies that uncovered the intracellular molecular mechanism. This review will also provide the latest evidence-based research progress in this field and suggest research directions for future experiments.

Musculoskeletal Regeneration, Rehabilitation, and Plasticity Following Traumatic Injury

Type of study: literature review

Number of citations: 37

Year: 2020

Authors: Sarah M Greising, B. Corona, J. Call

Journal: International Journal of Sports Medicine

Journal ranking: Q2

Key takeaways: Traumatic orthopedic injuries disrupt regenerative healing, affecting bone and skeletal muscle repair and regeneration, requiring innovative treatment and rehabilitation approaches for improved musculoskeletal health.

Abstract: Abstract The musculoskeletal system has an integral role throughout life, including structural support to the body, protection, and allowing a range of fine to complex movements for daily living to elite sporting events. At various times, injuries to the musculoskeletal system occur resulting in varying levels of impact to the person both acutely and chronically. Specifically, there is a spectrum of complexity in orthopedic injuries, with some such as common muscle strains, that while burdensome will have no impact on life-long functional ability, and others that can result in long lasting disability. Focusing on extremity injuries, this review highlights: i)the current impact of orthopedic injuries in sport and daily life; ii) the foundation of bone and skeletal muscle repair and regeneration; and iii) the disruptions in regenerative healing due to traumatic orthopedic injuries. This review seeks to maximize the broad and collective research impact on sport and traumatic orthopedic injuries in search of promoting ongoing innovation for treatment and rehabilitation approaches aimed to improve musculoskeletal health throughout life.

Recovery System After Training And Competitive Efforts

Type of study:

Number of citations: 0

Year: 2019

Authors: Veaceslav Manolachi

Journal:

Journal ranking: brak

Key takeaways: Personalised recovery through nutrition can enhance athletes' performance and recovery, with a focus on energy needs and musculoskeletal system restoration.

Abstract: Recovery begins where the effort ends, so we can define it as a rebalancing, return or regeneration of the body. Systems involved in the recovery process are those that maintain vital functions: blood pressure, heart rate, body temperature. At the same time, the internal environment is restored, the lactic acid accumulates, the accumulation of changes in the blood pH restoring the normal level of sugar in the blood. After a dynamic effort of maximal intensity and after short static efforts, it is necessary to restore the functions of the musculoskeletal system and CNS. When planning training efforts and competitive regimes, consideration is also given to the correlation between work and rest, in order for the subsequent efforts to return to the baseline stage or until the complete recovery. The aim of the research is to achieve personalised recovery through nutrition according to the chosen sport, paying attention to the energy needs demanded by the international competitions. The objectives of the research will be to change the mentality on nutritional factors before training, and the results recorded by the athletes will be based on scientific evidence of sports nutrition. Thus, the management of the recovery process with pharmaceutical preparations in the intensive training period requires the administration of a complex of potash and inosine, but they should be administered only on the doctor’s advice, in the case of maximal intensity efforts at medium altitude and only if the athlete’s functional condition is getting worse. © 2019 Published by Future Academy www.FutureAcademy.org.UK

Promoting musculoskeletal system soft tissue regeneration by biomaterial-mediated modulation of macrophage polarization

Type of study:

Number of citations: 57

Year: 2021

Authors: Jinchun Ye, Chang Xie, Canlong Wang, Jiayun Huang, Zi Yin, B. Heng, Xiao Chen, Weiliang Shen

Journal: Bioactive Materials

Journal ranking: Q1

Key takeaways: Biomaterials that actively modulate macrophage polarization can enhance musculoskeletal system soft tissue regeneration and provide alternative therapeutic options for repairing critical-sized defects.

Producing 3D Biomimetic Nanomaterials for Musculoskeletal System Regeneration

Type of study:

Number of citations: 22

Year: 2018

Authors: Ignasi Casanellas, Andrea García-Lizarribar, A. Lagunas, J. Samitier

Journal: Frontiers in Bioengineering and Biotechnology

Journal ranking: Q1

Key takeaways: 3D nanoengineered biomaterials show promise for musculoskeletal tissue regeneration, promoting interprotein communication and implant integration.

Abstract: The human musculoskeletal system is comprised mainly of connective tissues such as cartilage, tendon, ligaments, skeletal muscle, and skeletal bone. These tissues support the structure of the body, hold and protect the organs, and are responsible of movement. Since it is subjected to continuous strain, the musculoskeletal system is prone to injury by excessive loading forces or aging, whereas currently available treatments are usually invasive and not always effective. Most of the musculoskeletal injuries require surgical intervention facing a limited post-surgery tissue regeneration, especially for widespread lesions. Therefore, many tissue engineering approaches have been developed tackling musculoskeletal tissue regeneration. Materials are designed to meet the chemical and mechanical requirements of the native tissue three-dimensional (3D) environment, thus facilitating implant integration while providing a good reabsorption rate. With biological systems operating at the nanoscale, nanoengineered materials have been developed to support and promote regeneration at the interprotein communication level. Such materials call for a great precision and architectural control in the production process fostering the development of new fabrication techniques. In this mini review, we would like to summarize the most recent advances in 3D nanoengineered biomaterials for musculoskeletal tissue regeneration, with especial emphasis on the different techniques used to produce them.

Cell therapy to improve regeneration of skeletal muscle injuries

Type of study:

Number of citations: 119

Year: 2019

Authors: T. Qazi, G. Duda, M. Ort, C. Perka, S. Geissler, T. Winkler

Journal: Journal of Cachexia, Sarcopenia and Muscle

Journal ranking: Q1

Key takeaways: Cell-based approaches show promising results in treating traumatic muscle injuries, potentially addressing the unmet clinical need for effective treatment.

Abstract: Diseases that jeopardize the musculoskeletal system and cause chronic impairment are prevalent throughout the Western world. In Germany alone, ~1.8 million patients suffer from these diseases annually, and medical expenses have been reported to reach 34.2bn Euros. Although musculoskeletal disorders are seldom fatal, they compromise quality of life and diminish functional capacity. For example, musculoskeletal disorders incur an annual loss of over 0.8 million workforce years to the German economy. Among these diseases, traumatic skeletal muscle injuries are especially problematic because they can occur owing to a variety of causes and are very challenging to treat. In contrast to chronic muscle diseases such as dystrophy, sarcopenia, or cachexia, traumatic muscle injuries inflict damage to localized muscle groups. Although minor muscle trauma heals without severe consequences, no reliable clinical strategy exists to prevent excessive fibrosis or fatty degeneration, both of which occur after severe traumatic injury and contribute to muscle degeneration and dysfunction. Of the many proposed strategies, cell‐based approaches have shown the most promising results in numerous pre‐clinical studies and have demonstrated success in the handful of clinical trials performed so far. A number of myogenic and non‐myogenic cell types benefit muscle healing, either by directly participating in new tissue formation or by stimulating the endogenous processes of muscle repair. These cell types operate via distinct modes of action, and they demonstrate varying levels of feasibility for muscle regeneration depending, to an extent, on the muscle injury model used. While in some models the injury naturally resolves over time, other models have been developed to recapitulate the peculiarities of real‐life injuries and therefore mimic the structural and functional impairment observed in humans. Existing limitations of cell therapy approaches include issues related to autologous harvesting, expansion and sorting protocols, optimal dosage, and viability after transplantation. Several clinical trials have been performed to treat skeletal muscle injuries using myogenic progenitor cells or multipotent stromal cells, with promising outcomes. Recent improvements in our understanding of cell behaviour and the mechanistic basis for their modes of action have led to a new paradigm in cell therapies where physical, chemical, and signalling cues presented through biomaterials can instruct cells and enhance their regenerative capacity. Altogether, these studies and experiences provide a positive outlook on future opportunities towards innovative cell‐based solutions for treating traumatic muscle injuries—a so far unmet clinical need.

Fostering tissue engineering and regenerative medicine to treat musculoskeletal disorders in bone and muscle

Type of study:

Number of citations: 21

Year: 2024

Authors: Soyeon Park, Khandoker Asiqur Rahaman, Yu-Chan Kim, H. Jeon, Hyung-Seop Han

Journal: Bioactive Materials

Journal ranking: Q1

Key takeaways: Tissue engineering and regenerative medicine, using MSCs and ADSCs, biomaterials, and external stimuli, show potential in treating musculoskeletal disorders like osteoporosis, osteoarthritis, and muscular dystrophy.

Cellular senescence in musculoskeletal homeostasis, diseases, and regeneration

Type of study:

Number of citations: 88

Year: 2021

Authors: M. Wan, Elise F Gray-Gaillard, J. Elisseeff

Journal: Bone Research

Journal ranking: Q1

Key takeaways: Cellular senescence contributes to age-related musculoskeletal disorders, and targeting these cells may promote tissue repair and regeneration.

Current advances on the regeneration of musculoskeletal interfaces.

Type of study: literature review

Number of citations: 10

Year: 2020

Authors: W. Balestri, Rob Morris, J. Hunt, Y. Reinwald

Journal: Tissue engineering. Part B, Reviews

Journal ranking: Q1

Key takeaways: Recent advances in regeneration of musculoskeletal interfaces show promise for reducing graft instability, high morbidity, and pain in disorders and injuries.

Abstract: The regeneration of the musculoskeletal system has been widely investigated. There is now detailed knowledge about the organs composing this system. Research has also investigated the zones between individual tissues where physical, mechanical and biochemical properties transition. However, the understanding of the regeneration of musculoskeletal interfaces is still lacking behind. Numerous disorders and injuries can degrade or damage tissue interfaces. Their inability to regenerate can delay the tissue repair and regeneration process, leading to graft instability, high morbidity and pain. Moreover, the knowledge of the mechanism of tissue interface development is not complete. This review presents an overview of the most recent approaches of the regeneration of musculoskeletal interfaces, including the latest in vitro, preclinical and clinical studies.

Mesenchymal Stem Cells in the Musculoskeletal System: From Animal Models to Human Tissue Regeneration?

Type of study:

Number of citations: 51

Year: 2018

Authors: K. Čamernik, A. Barlič, M. Drobnič, J. Marc, M. Jeras, J. Zupan

Journal: Stem Cell Reviews and Reports

Journal ranking: Q2

Key takeaways: Mesenchymal stem cells (MSCs) play a crucial role in musculoskeletal regeneration and have potential applications in regenerative medicine and diagnostic markers for osteoporosis and osteoarthritis.

Abstract: The musculoskeletal system includes tissues that have remarkable regenerative capabilities. Bone and muscle sustain micro-damage throughout the lifetime, yet they continue to provide the body with the support that is needed for everyday activities. Our current understanding is that the regenerative capacity of the musculoskeletal system can be attributed to the mesenchymal stem/ stromal cells (MSCs) that reside within its different anatomical compartments. These MSCs can replenish various tissues with progenitor cells to form functional cells, such as osteoblasts, chondrocytes, myocytes, and others. However, with aging and in certain disorders of the musculoskeletal system such as osteoarthritis or osteoporosis, this regenerative capacity of MSCs appears to be lost or diverted for the production of other non-functional cell types, such as adipocytes and fibroblasts. In this review, we shed light on the tissue sources and subpopulations of MSCs in the musculoskeletal system that have been identified in animal models, discuss the mechanisms of their anti-inflammatory action as a prerequisite for their tissue regeneration and their current applications in regenerative medicine. While providing up-to-date evidence of the role of MSCs in different musculoskeletal pathologies, in particular in osteoporosis and osteoarthritis, we share some thoughts on their potential as diagnostic markers in musculoskeletal health and disease.

Editorial of Special Issue: Biological Basis of Musculoskeletal Regeneration 2019

Type of study:

Number of citations: 0

Year: 2020

Authors: Franka Klatte-Schulz, B. Wildemann

Journal: International Journal of Molecular Sciences

Journal ranking: Q1

Key takeaways: Musculoskeletal regeneration involves complex molecular and cellular mechanisms, with potential applications in bone, cartilage, tendon/ligament, and muscle regeneration.

Abstract: The Special Issue 'Biological Basis of Musculoskeletal Regeneration 2019' aimed to collect research and review articles that cover various aspects of the molecular and cellular mechanisms of bone, cartilage, tendon/ligament, and muscle regeneration [...].

Exploring cellular senescence in the musculoskeletal system: Any insights for biomarkers discovery?

Type of study:

Number of citations: 14

Year: 2023

Authors: L. Gerosa, A. Malvandi, M. Malavolta, M. Provinciali, G. Lombardi

Journal: Ageing Research Reviews

Journal ranking: Q1

Key takeaways: Cellular senescence in the musculoskeletal system negatively impacts muscle regeneration and bone turnover, leading to functional decline and early aging.

Gene therapy approaches to regenerating the musculoskeletal system

Type of study:

Number of citations: 193

Year: 2015

Authors: C. Evans, J. Huard

Journal: Nature Reviews Rheumatology

Journal ranking: Q1

Key takeaways: Gene therapy shows potential in improving repair and regeneration of the musculoskeletal system, with potential applications in osteoarthritis, cartilage repair, and bone-healing.

Adipose-Derived Mesenchymal Stem Cells: A Promising Tool in the Treatment of Musculoskeletal Diseases

Type of study:

Number of citations: 76

Year: 2019

Authors: M. Torres-Torrillas, Mónica Rubio, E. Damiá, Belén Cuervo, Ayla del Romero, P. Peláez, Deborah Chicharro, L. Miguel, J. Sopena

Journal: International Journal of Molecular Sciences

Journal ranking: Q1

Key takeaways: Adipose-derived mesenchymal stem cells show potential in treating musculoskeletal diseases, with potential applications in muscle, tendon, bone, and cartilage regeneration, but long-term safety and side effects remain unclear.

Abstract: Chronic musculoskeletal (MSK) pain is one of the most common medical complaints worldwide and musculoskeletal injuries have an enormous social and economical impact. Current pharmacological and surgical treatments aim to relief pain and restore function; however, unsatiscactory outcomes are commonly reported. In order to find an accurate treatment to such pathologies, over the last years, there has been a significantly increasing interest in cellular therapies, such as adipose-derived mesenchymal stem cells (AMSCs). These cells represent a relatively new strategy in regenerative medicine, with many potential applications, especially regarding MSK disorders, and preclinical and clinical studies have demonstrated their efficacy in muscle, tendon, bone and cartilage regeneration. Nevertheless, several worries about their safety and side effects at long-term remain unsolved. This article aims to review the current state of AMSCs therapy in the treatment of several MSK diseases and their clinical applications in veterinary and human medicine.

Recovery of the immune system after exercise.

Type of study:

Number of citations: 299

Year: 2017

Authors: J. Peake, Oliver Neubauer, N. Walsh, R. Simpson

Journal: Journal of applied physiology

Journal ranking: Q1

Key takeaways: Carbohydrate supplementation is the most effective strategy for minimizing immune disturbances during exercise recovery, while sleep is also crucial for optimal immune function.

Abstract: The notion that prolonged, intense exercise causes an 'open window' of immunodepression during recovery after exercise is well accepted. Repeated exercise bouts or intensified training without sufficient recovery may increase the risk of illness. However, except for salivary IgA, clear and consistent markers of this immunodepression remain elusive. Exercise increases circulating neutrophil and monocyte counts and reduces circulating lymphocyte count during recovery. This lymphopenia results from preferential egress of lymphocyte subtypes with potent effector functions [e.g., natural killer (NK) cells, γδ T cells, and CD8+ T cells]. These lymphocytes most likely translocate to peripheral sites of potential antigen encounter (e.g., lungs and gut). This redeployment of effector lymphocytes is an integral part of the physiological stress response to exercise. Current knowledge about changes in immune function during recovery from exercise is derived from assessment at the cell population level of isolated cells ex vivo or in blood. This assessment can be biased by large changes in the distribution of immune cells between blood and peripheral tissues during and after exercise. Some evidence suggests that reduced immune cell function in vitro may coincide with changes in vivo and rates of illness after exercise, but more work is required to substantiate this notion. Among the various nutritional strategies and physical therapies that athletes use to recover from exercise, carbohydrate supplementation is the most effective for minimizing immune disturbances during exercise recovery. Sleep is an important aspect of recovery, but more research is needed to determine how sleep disruption influences the immune system of athletes.

A bibliometric analytical study of research on the immune system and the stress of sports training

Type of study: literature review

Number of citations: 0

Year: 2025

Authors: Mohamed Sharaf, Samir Abdelnaby Shabaan Issa

Journal: International Sports Science Alexandria Journal

Journal ranking: brak

Key takeaways: Excessive sports training loads can weaken athletes' immune systems, while moderate-load, gradual physical exercises with appropriate rest periods improve immunity and enhance performance.

Abstract: : The study aims to identify the research that dealt with the immune system and the and sports stress of sports training and provide an overview of excessive training load and its effect on the immune system of athletes, as well as providing the best ways to intervene to prevent the negative consequences of excessive training load and means of strengthening the immune system. The researchers used the descriptive approach for studies that dealt with the immune system and sports training pressures. The number of studies that were referred to in the period from 2010 to 2023 AD was (82) studies. From the analysis of the studies, the researchers concluded that the most important research trends in this regard are that excessively increasing training loads leads to weakness and a decrease in the immune response and provides an opportunity for disease infection. The unregulated increase in loads is also associated with an increase in free oxygen radicals, which leads to damage not only to muscle cells and energy stores, but also to the response and activity of immune cells. In addition to the positive effect of moderate-load and gradual physical exercises with appropriate rest periods, they improve immunity, increase the ability of the body's systems to confront pathogens, and increase the efficiency of immune cells that work to repair cells. The affected during resistance exercises, which increases their ability to perform. Researchers also recommend the need to pay attention to the specificity of training loads and also rest periods, whether between daily training units and within them, between training days, between small and large training sessions, and between competition and match days, and to pay attention to the recovery process, in addition to regulating sleep, diet, nutritional supplements, rest periods during sports practice, environmental, physical and psychological pressures, motor activity, genetic factors, and healthy lifestyle.

Alterations in the innate immune system due to exhausting exercise in intensively trained rats

Type of study: non-rct experimental

Number of citations: 26

Year: 2020

Authors: Sheila Estruel-Amades, Mariona Camps-Bossacoma, M. Massot-Cladera, F. Pérez-Cano, M. Castell

Journal: Scientific Reports

Journal ranking: Q1

Key takeaways: A 5-week intense training program, but not a shorter training, induced alterations in the innate immune system functionality in rats.

DOES HIGH-INTENSITY RESISTANCE TRAINING AFFECT AN ATHLETE'S IMMUNE FUNCTIONS?

Type of study:

Number of citations: 0

Year: 2024

Authors: Mohammed Mohammed, Kamil Aboshkair, May Salem

Journal: Journal of Engineering, Management and Information Technology

Journal ranking: brak

Key takeaways: High-intensity resistance training may negatively impact an athlete's immune system, requiring sufficient rest and recovery to prevent upper respiratory tract infections.

Abstract: This research aims to comprehensively examine the latest literature on the effects of high-intensity resistance training on the immune system's long-term performance. Many athletes and active individuals believe that moderate physical activity can enhance resistance to minor illnesses like upper respiratory tract infections (URTI), while intense exercise may have the opposite effect. The study involved 90 athletes who regularly train at Ahly Sporting Club and were divided into three groups: Group 1 included 30 athletes at rest, Group 2 comprised 30 athletes after normal training, and Group 3 had 30 athletes after intense training. Athletes who undergo intense training have lower total white blood cell counts than those who train at normal or resting levels. However, their neutrophil numbers slightly increase after heavy training, while lymphocyte and natural killer cell levels decrease. Additionally, those who undergo heavy training have higher PHA-induced proliferation levels but show a decline in serum immunoglobulin levels, mucosal immunoglobulin concentrations, and plasma glutamine levels. To prevent upper respiratory tract infections in athletes, it is essential to avoid over training and provide sufficient rest and recovery during and after training and competition. It is currently uncertain whether moderate exercise training can prevent infectious illness among the general population.

Effect of Acute High-Intensity Interval Training on Immune Function and Oxidative Stress in Canoe/Kayak Athletes

Type of study: non-rct experimental

Number of citations: 6

Year: 2023

Authors: Ting-Ting Lee, Tzai-li Li, Bo-Jen Ko, Li-Hui Chien

Journal: Biology

Journal ranking: Q1

Key takeaways: Acute kayak HIIT can temporarily suppress immune function and induce oxidative stress in athletes, highlighting the need for proper recovery periods and training frequency.

Abstract: Simple Summary High-intensity interval training (HIIT) is a primary training method for canoe/kayak athletes to enhance physical performance. However, intense training regimens can cause immunosuppression due to inflammation, metabolic stress, and oxidative stress. This study aimed to examine the effects of kayaking/canoeing HIIT exercise on immune and oxidative stress measures in athletes. Results showed that acute sprinting interval training on a kayak can affect immune cell count and oxidative stress biomarkers. Coaches and sports science professionals should consider these findings, as high training frequency or inadequate recovery periods between HIIT sessions can temporarily suppress immune function. Abstract The aim of this study was to investigate the effects of acute high-intensity interval training (HIIT) on immune function and oxidative stress in male canoe/kayak athletes who were well trained. A total of 22 participants were voluntarily recruited with an age range of 15.9 ± 2.3 years, height of 172.2 ± 5.5 cm, body mass of 63.30 ± 6.95 kg, and body fat of 13.77 ± 3.76%. The modified Wingate kayaking test on a kayak ergometer was performed by all participants. Blood samples were collected at three different time points: before the test (Pre-T), immediately after (Post-T), and 3 h post-test (Post-3 h). Saliva samples were collected at two different time points: before the test (Pre-T) and 3 h after the test (Post-3 h). Results indicated that acute canoe/kayak ergometry HIIT had significant effects on the percentages and counts of leukocytes, neutrophils, lymphocytes, and lymphocyte subsets. Additionally, it resulted in increased total LPS-stimulated neutrophil elastase release and alterations in plasma concentrations of superoxide dismutase, catalase, and TBARS. These findings suggest that conventional kayak HIIT regimens can have short-term effects on immune function and induce oxidative stress in athletes.

Chronic exercise training effects on immune function.

Type of study: literature review

Number of citations: 244

Year: 2000

Authors: L. Mackinnon

Journal: Medicine and science in sports and exercise

Journal ranking: Q1

Key takeaways: Prolonged intense exercise may slightly impair immune parameters, potentially compromising resistance to minor illnesses like upper respiratory tract infection, while moderate exercise has no effect or may stimulate these immune parameters.

Abstract: PURPOSE This paper reviews the recent literature on the chronic effects of exercise training on immune function in humans. There is a general perception by athletes and other physically active individuals that regular moderate activity enhances, whereas intense exercise suppresses, resistance to minor illnesses such as upper respiratory tract infection (URTI). This perception is supported by epidemiological data in endurance athletes and limited data from intervention studies using moderate exercise in previously untrained individuals. The apparently high incidence of URTI among endurance athletes has prompted interest the relationship between chronic exercise training and immune function. Whereas immune cell number is generally normal during intense exercise training, recent evidence suggests that prolonged periods of intense training may lead to slight impairment in immune parameters such as neutrophil function, serum and mucosal immunoglobulin levels, plasma glutamine concentration, and possibly natural killer cell cytotoxic activity. In contrast. moderate exercise training has either no effect on, or may stimulate, these immune parameters. CONCLUSION Whereas athletes are not clinically immune deficient, it is possible that the combined effects of small changes in several immune parameters may compromise resistance to minor illnesses such as URTI. Strategies to prevent URTI in athletes include avoiding overtraining, providing adequate rest and recovery during the training cycle and after competition, limiting exposure to sources of infection, ensuring adequate nutrition, and possibly vitamin C supplementation. It is uncertain at present whether moderate exercise training is helpful in preventing infectious illness among the wider population.

Lymphocyte and dendritic cell response to a period of intensified training in young healthy humans and rodents: A systematic review and meta-analysis

Type of study: meta-analysis

Number of citations: 4

Year: 2022

Authors: C. Baker, J. Hunt, J. Piasecki, J. Hough

Journal: Frontiers in Physiology

Journal ranking: Q2

Key takeaways: Intensified training may decrease lymphocyte and dendritic cell counts, but definitive immune biomarkers are limited and further investigation is needed to confirm dendritic cell response in human models.

Abstract: Background: Intensified training coupled with sufficient recovery is required to improve athletic performance. A stress-recovery imbalance can lead to negative states of overtraining. Hormonal alterations associated with intensified training, such as blunted cortisol, may impair the immune response. Cortisol promotes the maturation and migration of dendritic cells which subsequently stimulate the T cell response. However, there are currently no clear reliable biomarkers to highlight the overtraining syndrome. This systematic review and meta-analysis examined the effect of intensified training on immune cells. Outcomes from this could provide insight into whether these markers may be used as an indicator of negative states of overtraining. Methods: SPORTDiscus, PUBMED, Academic Search Complete, Scopus and Web of Science were searched until June 2022. Included articles reported on immune biomarkers relating to lymphocytes, dendritic cells, and cytokines before and after a period of intensified training, in humans and rodents, at rest and in response to exercise. Results: 164 full texts were screened for eligibility. Across 57 eligible studies, 16 immune biomarkers were assessed. 7 were assessed at rest and in response to a bout of exercise, and 9 assessed at rest only. Included lymphocyte markers were CD3+, CD4+ and CD8+ T cell count, NK cell count, NK Cytolytic activity, lymphocyte proliferation and CD4/CD8 ratio. Dendritic cell markers examined were CD80, CD86, and MHC II expression. Cytokines included IL-1β, IL-2, IL-10, TNF-α and IFN-γ. A period of intensified training significantly decreased resting total lymphocyte (d= −0.57, 95% CI −0.30) and CD8+ T cell counts (d= −0.37, 95% CI −0.04), and unstimulated plasma IL-1β levels (d= −0.63, 95% CI −0.17). Resting dendritic cell CD86 expression significantly increased (d = 2.18, 95% CI 4.07). All other biomarkers remained unchanged. Conclusion: Although some biomarkers alter after a period of intensified training, definitive immune biomarkers are limited. Specifically, due to low study numbers, further investigation into the dendritic cell response in human models is required.

A Guide to Different Intensities of Exercise, Vaccination, and Sports Nutrition in the Course of Preparing Elite Athletes for the Management of Upper Respiratory Infections during the COVID-19 Pandemic: A Narrative Review

Type of study: systematic review

Number of citations: 17

Year: 2022

Authors: H. Agha-alinejad, Amir Hossein Ahmadi Hekmatikar, Ruheea Taskin Ruhee, M. Shamsi, M. Rahmati, Kayvan Khoramipour, Katsuhiko Suzuki

Journal: International Journal of Environmental Research and Public Health

Journal ranking: Q2

Key takeaways: Elite athletes should maintain physical fitness during COVID-19 by using low- and moderate-intensity training, avoiding high-intensity training, and incorporating nutritional strategies to improve immune function.

Abstract: Elite athletes use high-intensity training to maintain their fitness level. However, intense training can harm the immune system, making athletes suspectable to COVID-19 and negatively affecting their performance. In addition, the diet of athletes should be appreciated more as it is another influencer of the immune system, especially during the COVID 19 pandemic. The other important issue elite athletes face currently is vaccination and its possible intervention with their training. The present study attempts to discuss the impact of different training intensities, nutritional strategies, and vaccination on the immune system function in elite athletes. To this end, Scopus, ISC, PubMed, Web of Science, and Google Scholar databases were searched from 1988 to 2021 using the related keywords. The results of our review showed that although high-intensity exercise can suppress the immune system, elite athletes should not stop training in the time of infection but use low- and moderate-intensity training. Moderate-intensity exercise can improve immune function and maintain physical fitness. In addition, it is also better for athletes not to undertake high-intensity training at the time of vaccination, but instead perform moderate to low-intensity training. Furthermore, nutritional strategies can be employed to improve immune function during high-intensity training periods.

Sports and Immunity, from the recreational to the elite athlete.

Type of study:

Number of citations: 6

Year: 2024

Authors: Richard Baskerville, Linda Castell, Stéphane François Bermon

Journal: Infectious diseases now

Journal ranking: Q2

Key takeaways: Exercise enhances immune health and promotes healthy lifestyles, but excessive training, mental stress, and insufficient recovery can negatively impact performance and general health.

Overtraining effects on immunity and performance in athletes

Type of study:

Number of citations: 234

Year: 2000

Authors: L. Mackinnon

Journal: Immunology and Cell Biology

Journal ranking: Q2

Key takeaways: Overtraining syndrome in athletes can lead to poor performance, immune suppression, and increased illness, but its cause remains unclear.

Abstract: Overtraining is a process of excessive exercise training in high‐performance athletes that may lead to overtraining syndrome. Overtraining syndrome is a neuroendocrine disorder characterized by poor performance in competition, inability to maintain training loads, persistent fatigue, reduced catecholamine excretion, frequent illness, disturbed sleep and alterations in mood state. Although high‐performance athletes are generally not clinically immune deficient, there is evidence that several immune parameters are suppressed during prolonged periods of intense exercise training. These include decreases in neutrophil function, serum and salivary immunoglobulin concentrations and natural killer cell number and possibly cytotoxic activity in peripheral blood. Moreover, the incidence of symptoms of upper respiratory tract infection increases during periods of endurance training. However, all of these changes appear to result from prolonged periods of intense exercise training, rather than from the effects of overtraining syndrome itself. At present, there is no single objective marker to identify overtraining syndrome. It is best identified by a combination of markers, such as decreases in urinary norepinephrine output, maximal heart rate and blood lactate levels, impaired sport performance and work output at 110% of individual anaerobic threshold, and daily self‐analysis by the athlete (e.g. high fatigue and stress ratings). The mechanisms underlying overtraining syndrome have not been clearly identified, but are likely to involve autonomic dysfunction and possibly increased cytokine production resulting from the physical stress of intense daily training with inadequate recovery.

Is Micronutrient Supplementation Helpful in Supporting the Immune System during Prolonged, High-Intensity Physical Training?

Type of study:

Number of citations: 2

Year: 2024

Authors: Francesca Felice, R. Moschini, M. Cappiello, Gemma Sardelli, Rossella Mosca, Lucia Piazza, F. Balestri

Journal: Nutrients

Journal ranking: Q1

Key takeaways: Micronutrient supplementation with diet can help protect the immune system from stress effects induced by intense physical activities.

Abstract: It is well known that during prolonged, high-intensity physical training, athletes experience a state of immunosuppression and that balanced nutrition can help maintain immunity. This review summarizes the effects (amplified by virus infection) of high-intensity, long-term exercise on immunity, critically presenting key micronutrients and supplementation strategies that can influence athletes’ performance and their immune system. The main conclusion is that micronutrient supplementation with diet could help to protect the immune system from the stress effects induced by intense physical activities. The importance of personalized supplementation has been also recommended.

The impact of different training intensities on athletes' immune system function and the management of upper respiratory traction infections: a narrative review

Type of study: systematic review

Number of citations: 5

Year: 2023

Authors: Reza Sabzevari Rad

Journal: Sport Sciences for Health

Journal ranking: Q3

Key takeaways: Regular and moderate-intensity training can reduce the risk of upper respiratory tract infections, improve immune function, and physical fitness, while prolonged and high-intensity training can increase the risk and negatively affect performance.

Abstract: Athletes employ high-intensity training to promote their physical fitness. However, high-intensity training can harm the immune system, making athletes susceptible to URTI, and negatively affecting their performance in sports. In addition, the athlete’s diet should be paid more attention to as it is another issue influencing the immune system, especially during the URTI. The present study attempts to discuss the impact of different training intensities on athletes' immune system function, as well as the management of upper respiratory traction infections. An online search was done in web of science (WoS), Ovid, Scopus, and PubMed (MeSH) databases with the following combination of keywords: “Upper Respiratory Tract Infections”, “Exercise Training”, and “Athletes”. The results of our overview showed that regular and moderate-intensity training can reduce the relative risk of URTI, improve immune function and physical fitness. Moreover, we found that prolonged and high-intensity training can increase the relative risk of URTI, which leads to a decrease in aerobic performance, and also lessens physical fitness. Although high-intensity training can suppress the immune system, elite athletes should not stop training during the time of URTI. Based on the available evidence, it may be recommended to exercise during the URTI outbreak. Therefore, the first step in managing athletes’ URTI is to reduce exercise intensity (the open window hypothesis may actually increase the susceptibility to URTI), with the utilization of nutritional strategies as the second step. However, athletes with severe and major URTI symptoms (e.g., severe sore throat, fever, cough, myalgia, shortness of breath, general fatigue) should avoid training and must have active rest (i.e., low-intensity exercise), as well as protein supplementation and low-intensity resistance training. Third, athletes with mild and minor URTI symptoms (e.g., runny nose, sinus congestion, mild sore throat) can perform aerobic training and moderate-intensity training, and benefit from improved immune function according to the J-shaped model. Functional nutritional strategies include avoiding sudden dietary changes, receiving 50% of total daily calories from carbohydrates consumption: 30–90 g/h in competitions (depending on the intensity and duration of exercise), protein consumption: 1.3 to 1.8 g/kg bw/day, flavonoids intake, herbal supplements intake, probiotic supplementation intake, and taking vitamins C and D.

Immune adaptation to chronic intense exercise training: new microarray evidence

Type of study: non-rct observational study

Number of citations: 42

Year: 2017

Authors: Dongmei Liu, Ru Wang, A. Grant, Jinming Zhang, P. Gordon, Yuqin Wei, Peijie Chen

Journal: BMC Genomics

Journal ranking: Q1

Key takeaways: In young healthy individuals, intense endurance exercise training can chronically induce transcriptional changes in peripheral blood leukocytes, upregulating protein production and mitochondrial energetics, and downregulating inflammatory response.

Abstract: Endurance exercise training, especially the high-intensity training, exhibits a strong influence on the immune system. However, the mechanisms underpinning the immune-regulatory effect of exercise remain unclear. Consequently, we chose to investigate the alterations in the transcriptional profile of blood leukocytes in young endurance athletes as compared with healthy sedentary controls, using Affymetrix human gene 1.1 ST array. Group differences in the transcriptome were analyzed using Intensity-based Hierarchical Bayes method followed by a Logistic Regression-based gene set enrichment method. We identified 72 significant transcripts differentially expressed in the leukocyte transcriptome of young endurance athletes as compared with non-athlete controls with a false discovery rate (FDR) < 0.05, comprising mainly the genes encoding ribosomal proteins and the genes involved in mitochondrial oxidative phosphorylation. Gene set enrichment analysis identified three major gene set clusters: two were up-regulated in athletes including gene translation and ribosomal protein production, and mitochondria oxidative phosphorylation and biogenesis; one gene set cluster identified as transcriptionally downregulated in athletes was related to inflammation and immune activity. Our data indicates that in young healthy individuals, intense endurance exercise training (exemplifed by athletic training) can chronically induce transcriptional changes in the peripheral blood leukocytes, upregulating genes related to protein production and mitochondrial energetics, and downregulating genes involved in inflammatory response. The findings of the study also provide support for the notion that peripheral blood can be used as a surrogate tissue to study the systemic effect of exercise training.

Immunological Response to Exercise in Athletes with Disabilities: A Narrative Review of the Literature

Type of study: literature review

Number of citations: 3

Year: 2023

Authors: M. Sellami, L. Puce, N. Bragazzi

Journal: Healthcare

Journal ranking: brak

Key takeaways: Exercise-induced immune responses in disabled athletes are complex, with moderate intensity workouts promoting optimal immunity and resistance to infections, while intense training with inadequate recovery can cause temporary immunosuppression.

Abstract: For a person with a disability, participating in sports activities and/or competitions can be a challenge for the immune system. The relationship between exercise and immunity response in disabled athletes is, indeed, extremely complex for several reasons, including (1) the chronic low-grade inflammatory and immunodepression—“secondary immune deficiency”—state imposed by the disability/impairment; (2) the impact of the disability on an array of variables, spanning from physical fitness to well-being, quality of life, sleep, and nutritional aspects, among others, which are known to mediate/modulate the effects of exercise on human health; (3) the variability of the parameters related to the exercise/physical activity (modality, frequency, intensity, duration, training versus competition, etc.); and (4) the intra- and inter-individual variability of the immunological response to exercise. In able-bodied athletes, previously published data described several exercise-induced changes affecting various immunological subsets and subpopulations, ranging from neutrophils to lymphocytes, and monocytes. Broadly, moderate intensity workout is accompanied by optimal immunity and resistance to infections such as upper respiratory tract infections (URTI) in athletes. Periods of intense training with insufficient recovery can cause a temporary state of immunosuppression, which should end with a few days of rest/recovery from exercise. Disabled athletes are relatively overlooked and understudied with respect to their able-bodied counterparts. Findings from the few studies available on paralympic and disabled athletes are here summarized and analyzed utilizing a narrative approach to review and determine the major features of the immunological and inflammatory responses to exercise in this specific population. Moreover, a few studies have reported behavioral, dietary, and training strategies that can be adopted to limit exercise-induced immunosuppression and reduce the risk of infection in people with disabilities. However, given the paucity of data and contrasting findings, future high-quality investigations on paralympic and disabled athletes are urgently needed.

Can exercise affect immune function to increase susceptibility to infection?

Type of study:

Number of citations: 304

Year: 2020

Authors: R. Simpson, John P Campbell, M. Gleeson, K. Krüger, D. Nieman, D. Pyne, J. Turner, N. Walsh

Journal: Exercise immunology review

Journal ranking: Q1

Key takeaways: Arduous exercise may increase infection risk in athletes, but its impact on immunity is influenced by other factors, not just exercise itself.

Abstract: Multiple studies in humans and animals have demonstrated the profound impact that exercise can have on the immune system. There is a general consensus that regular bouts of short-lasting (i.e. up to 45 minutes) moderate intensity exercise is beneficial for host immune defense, particularly in older adults and people with chronic diseases. In contrast, infection burden is reported to be high among high performance athletes and second only to injury for the number of training days lost during preparation for major sporting events. This has shaped the common view that arduous exercise (i.e. those activities practiced by high performance athletes/ military personnel that greatly exceed recommended physical activity guidelines) can suppress immunity and increase infection risk. However, the idea that exercise per se can suppress immunity and increase infection risk independently of the many other factors (e.g. anxiety, sleep disruption, travel, exposure, nutritional deficits, environmental extremes, etc.) experienced by these populations has recently been challenged. The purpose of this debate article was to solicit opposing arguments centered around this fundamental question in the exercise immunology field: can exercise affect immune function to increase susceptibility to infection. Issues that were contested between the debating groups include: (i) whether or not athletes are more susceptible to infection (mainly of the upper respiratory tract) than the general population; (ii) whether exercise per se is capable of altering immunity to increase infection risk independently of the multiple factors that activate shared immune pathways and are unique to the study populations involved; (iii) the usefulness of certain biomarkers and the interpretation of in vitro and in vivo data to monitor immune health in those who perform arduous exercise; and (iv) the quality of scientific evidence that has been used to substantiate claims for and against the potential negative effects of arduous exercise on immunity and infection risk. A key point of agreement between the groups is that infection susceptibility has a multifactorial underpinning. An issue that remains to be resolved is whether exercise per se is a causative factor of increased infection risk in athletes. This article should provide impetus for more empirical research to unravel the complex questions that surround this contentious issue in the field of exercise immunology.

Wielokierunkowy wpływ wysiłku fizycznego na układ immunologiczny u sportowców wyczynowych

Type of study:

Number of citations: 0

Year: 2024

Authors: Macura, Szczepanik

Journal: Sztuka Leczenia

Journal ranking: brak

Key takeaways: Extreme physical activity significantly impacts athletes' immune systems, affecting blood leukocytes, respiratory and gut lymphoid tissue, and playing a role in muscle regeneration after training injuries.

Abstract: The extreme physical effort and psychological stress are everyday challenges faced by athletes. The regular training results in adaptation to increasing physical effort. It contributes to changes in various organs and metabolic processes. Intense physical training has been shown to affect numerous body systems including the immune system. The aim of this paper is to present the influence of extreme physical activity on various aspects of immune response. The changes in the immune system of athletes include not only those related to blood leukocytes, but those in connection to respiratory and gut associated lymphoid tissue as well. Moreover, the immune cells play an important role in muscle regeneration after sustaining training injury. The mmunology of physicial activity – mainly extreme physical activity – is a new, not fully recognized yet field of research. The understanding of these interactions facilitates a proper training planning for different groups of athletes.

Effect of Exercise Intensity on Cell-Mediated Immunity

Type of study:

Number of citations: 39

Year: 2021

Authors: Katsuhiko Suzuki, Harumi Hayashida

Journal: Sports

Journal ranking: Q1

Key takeaways: Low-intensity short-duration exercise does not significantly affect cell-mediated immunity, while high-intensity exercise may reduce it.

Abstract: Moderate-intensity exercise is considered to enhance immune function and to be useful for preventing acute upper respiratory infections and similar conditions. Many people practice low-intensity short-duration exercise with the expectation of a beneficial effect on immunocompetency. However, it is difficult to affirm the existence of definite evidence of such a benefit. In this article, we discuss the effects of low-intensity short-duration exercise on cell-mediated immunity, and contrast them to the effects of high-intensity and long-duration exercise. Whereas high-intensity exercise induces inflammation and reduces cell-mediated immune system function, low-intensity exercise does not appear to have a large effect on either inflammation or cell-mediated immune function. Low-intensity exercises such as walking and yoga, which are helpful to relieve stress, cannot be considered as harmful to the immune system. Although yoga was shown to impose fewer restrictions on breathing and physical strain, the evidence that yoga enhances cell-mediated immunity remains insufficient. Therefore, further studies are needed to examine the exercise mode that may be most effective for improvement of immune functions.

Molecular Pathways Mediating Immunosuppression in Response to Prolonged Intensive Physical Training, Low-Energy Availability, and Intensive Weight Loss

Type of study: rct

Number of citations: 37

Year: 2019

Authors: H. V. Sarin, I. Gudelj, J. Honkanen, J. Ihalainen, A. Vuorela, Joseph H. Lee, Zhenzhen Jin, J. Terwilliger, V. Isola, J. Ahtiainen, K. Häkkinen, Julija Jurić, G. Lauc, K. Kristiansson, J. Hulmi, M. Perola

Journal: Frontiers in Immunology

Journal ranking: Q1

Key takeaways: Prolonged intense training with low-energy availability leads to immunosuppression in normal weight individuals, with most immune system parameters returning to baseline after weight regain.

Abstract: Exercise and exercise-induced weight loss have a beneficial effect on overall health, including positive effects on molecular pathways associated with immune function, especially in overweight individuals. The main aim of our study was to assess how energy deprivation (i.e., “semi-starvation”) leading to substantial fat mass loss affects the immune system and immunosuppression in previously normal weight individuals. Thus, to address this hypothesis, we applied a high-throughput systems biology approach to better characterize potential key pathways associated with immune system modulation during intensive weight loss and subsequent weight regain. We examined 42 healthy female physique athletes (age 27.5 ± 4.0 years, body mass index 23.4 ± 1.7 kg/m2) volunteered into either a diet group (n = 25) or a control group (n = 17). For the diet group, the energy intake was reduced and exercise levels were increased to induce loss of fat mass that was subsequently regained during a recovery period. The control group was instructed to maintain their typical lifestyle, exercise levels, and energy intake at a constant level. For quantification of systems biology markers, fasting blood samples were drawn at three time points: baseline (PRE), at the end of the weight loss period (MID 21.1 ± 3.1 weeks after PRE), and at the end of the weight regain period (POST 18.4 ± 2.9 weeks after MID). In contrast to the control group, the diet group showed significant (false discovery rate <0.05) alteration of all measured immune function parameters—white blood cells (WBCs), immunoglobulin G glycome, leukocyte transcriptome, and cytokine profile. Integrative omics suggested effects on multiple levels of immune system as dysregulated hematopoiesis, suppressed immune cell proliferation, attenuated systemic inflammation, and loss of immune cell function by reduced antibody and chemokine secretion was implied after intense weight loss. During the weight regain period, the majority of the measured immune system parameters returned back to the baseline. In summary, this study elucidated a number of molecular pathways presumably explaining immunosuppression in individuals going through prolonged periods of intense training with low-energy availability. Our findings also reinforce the perception that the way in which weight loss is achieved (i.e., dietary restriction, exercise, or both) has a distinct effect on how the immune system is modulated.

Sports and immunity: Analyzing the relationship between physical activity and immune response in athletes

Type of study: systematic review

Number of citations: 0

Year: 2024

Authors: Dally Rahman

Journal: Jurnal Patriot

Journal ranking: brak

Key takeaways: Moderate exercise supports immune health in athletes, while intense exercise may suppress it, requiring athletes to balance training intensity and monitor immune markers for optimal health and performance.

Abstract: Problem: Physical activity has a complex relationship with immune function in athletes, where moderate exercise is generally beneficial, but intense training may suppress immunity. This systematic literature review examines how different exercise intensities impact immune responses in athletes, aiming to identify optimal training parameters for immune health. Purpose: The aim of this systematic literature review is to analyze the effects of various exercise intensities on immune function in athletes to determine training parameters that support optimal immune health. Methods: This study utilized a systematic literature review approach, gathering and analyzing scientific articles on the effects of exercise on athlete immune function. Articles were sourced from Scopus using search terms such as 'Exercise,' 'Physical Activity,' 'Sports,' and 'Immune Response,' with a focus on studies published within the past five years that evaluate exercise interventions on immune enhancement in athletes. After collecting relevant articles, descriptive analysis was conducted to identify consistent patterns and findings. Results: Intense and prolonged exercise can lead to immunosuppression in athletes, increasing susceptibility to infections and chronic conditions. However, moderate exercise enhances immune function, promoting beneficial responses such as improved lymphocyte distribution and antibody production post-vaccination. Key immune markers like NLR, PLR, and SII offer valuable insights into athletes’ immune status and can assist in monitoring health and performance. Conclusion: Moderate exercise supports immune health, while intense exercise may suppress it. Athletes should balance training intensity and monitor immune markers to maintain optimal health and performance.

Exercise and the immune system: implications for elite athletes and the general population

Type of study:

Number of citations: 13

Year: 2016

Authors: Graeme I. Lancaster, M. Febbraio

Journal: Immunology and Cell Biology

Journal ranking: Q2

Key takeaways: Too little or too much exercise can depress the immune system, posing challenges for athletes and the general population.

Assessment of Fatigue and Recovery in Male and Female Athletes After 6 Days of Intensified Strength Training

Type of study: non-rct experimental

Number of citations: 73

Year: 2016

Authors: C. Raeder, T. Wiewelhove, Rauno Álvaro de Paula Simola, M. Kellmann, T. Meyer, M. Pfeiffer, A. Ferrauti

Journal: Journal of Strength and Conditioning Research

Journal ranking: Q1

Key takeaways: A 6-day intensified strength training microcycle significantly reduces muscle strength, power, and jump efficiency, but recovery is rapid and complete.

Abstract: Abstract Raeder, C, Wiewelhove, T, Simola, RÁDP, Kellmann, M, Meyer, T, Pfeiffer, M, and Ferrauti, A. Assessment of fatigue and recovery in male and female athletes after 6 days of intensified strength training. J Strength Cond Res 30(12): 3412–3427, 2016—This study aimed to analyze changes of neuromuscular, physiological, and perceptual markers for routine assessment of fatigue and recovery in high-resistance strength training. Fourteen male and 9 female athletes participated in a 6-day intensified strength training microcycle (STM) designed to purposefully overreach. Maximal dynamic strength (estimated 1 repetition maximum [1RMest]; criterion measure of fatigue and recovery); maximal voluntary isometric strength (MVIC); countermovement jump (CMJ) height; multiple rebound jump (MRJ) height; jump efficiency (reactive strength index, RSI); muscle contractile properties using tensiomyography including muscle displacement (Dm), delay time (Td), contraction time (Tc), and contraction velocity (V90); serum concentration of creatine kinase (CK); perceived muscle soreness (delayed-onset muscle soreness, DOMS) and perceived recovery (physical performance capability, PPC); and stress (MS) were measured before and after the STM and after 3 days of recovery. After completing the STM, there were significant (p ⩽ 0.05) performance decreases in 1RMest (%[INCREMENT] ± 90% confidence limits, ES = effect size; −7.5 ± 3.5, ES = −0.21), MVIC (−8.2 ± 4.9, ES = −0.24), CMJ (−6.4 ± 2.1, ES = −0.34), MRJ (−10.5 ± 3.3, ES = −0.66), and RSI (−11.2 ± 3.8, ES = −0.73), as well as significantly reduced muscle contractile properties (Dm, −14.5 ± 5.3, ES = −0.60; V90, −15.5 ± 4.9, ES = −0.62). After days of recovery, a significant return to baseline values could be observed in 1RMest (4.3 ± 2.8, ES = 0.12), CMJ (5.2 ± 2.2, ES = 0.28), and MRJ (4.9 ± 3.8, ES = 0.32), whereas RSI (−7.9 ± 4.5, ES = −0.50), Dm (−14.7 ± 4.8, ES = −0.61), and V90 (−15.3 ± 4.7, ES = −0.66) remained significantly reduced. The STM also induced significant changes of large practical relevance in CK, DOMS, PPC, and MS before to after training and after the recovery period. The markers Td and Tc remained unaffected throughout the STM. Moreover, the accuracy of selected markers for assessment of fatigue and recovery in relation to 1RMest derived from a contingency table was inadequate. Correlational analyses also revealed no significant relationships between changes in 1RMest and all analyzed markers. In conclusion, mean changes of performance markers and CK, DOMS, PPC, and MS may be attributed to STM-induced fatigue and subsequent recovery. However, given the insufficient accuracy of markers for differentiation between fatigue and recovery, their potential applicability needs to be confirmed at the individual level.

Neuromuscular Fatigue and Recovery after Heavy Resistance, Jump, and Sprint Training

Type of study: non-rct experimental

Number of citations: 61

Year: 2018

Authors: Kevin Thomas, C. Brownstein, Jack Dent, P. Parker, S. Goodall, G. Howatson

Journal: Medicine & Science in Sports & Exercise

Journal ranking: Q1

Key takeaways: Strength, jump, and sprint training with repeated maximum efforts cause fatigue that takes up to 72 hours to fully resolve, but is not primarily due to central nervous system function decrements.

Abstract: Purpose Training methods that require maximal intensity efforts against light and heavy resistance are commonly used for athletic development. Typically, these sessions are separated by at least 48 h recovery on the assumption that such efforts elicit marked fatigue of the central nervous system (CNS), but this posit has not been well studied. The aim of the study was to assess the etiology and recovery of fatigue after heavy-resistance (strength), jump, and sprint training methods. Methods Ten male athletes completed three training sessions requiring maximal efforts that varied in their loading characteristics: (i) heavy-resistance exercise (10 × 5 back squats at 80% one-repetition maximum [1RM]) (STR), (ii) jumping exercise (10 × 5 jump squats) (JUMP), and (iii) maximal sprinting (15 × 30 m) (SPR). Preparticipants, postparticipants, and 24-, 48-, and 72-h postparticipants completed a battery of tests to measure neuromuscular function using electrical stimulation of the femoral nerve, and single- and paired-pulse magnetic stimulation of the motor cortex, with evoked responses recorded from the knee extensors. Fatigue was self-reported at each time point using a visual analog scale. Results Each intervention elicited fatigue that resolved by 48 (JUMP) and 72 h (STR and SPR). Decrements in muscle function (reductions in the potentiated quadriceps twitch force) persisted for 48 h after all exercise. Reductions in voluntary activation were present for 24 h after JUMP and SPRINT, and 48 h after STR. No other differences in CNS function were observed as a consequence of training. Conclusion Strength, jump, and sprint training requiring repeated maximum efforts elicits fatigue that requires up to 72 h to fully resolve, but this fatigue is not primarily underpinned by decrements in CNS function.

Markers for Routine Assessment of Fatigue and Recovery in Male and Female Team Sport Athletes during High-Intensity Interval Training

Type of study: non-rct experimental

Number of citations: 118

Year: 2015

Authors: T. Wiewelhove, C. Raeder, T. Meyer, M. Kellmann, M. Pfeiffer, A. Ferrauti

Journal: PLoS ONE

Journal ranking: Q1

Key takeaways: HIIT-induced fatigue and recovery in athletes are related to changes in neuromuscular function, CK, and DOMS, but the accuracy of using these markers for individual assessment needs further verification.

Abstract: Aim Our study aimed to investigate changes of different markers for routine assessment of fatigue and recovery in response to high-intensity interval training (HIIT). Methods 22 well-trained male and female team sport athletes (age, 23.0 ± 2.7 years; V̇O2max, 57.6 ± 8.6 mL·min·kg−1) participated in a six-day running-based HIIT-microcycle with a total of eleven HIIT sessions. Repeated sprint ability (RSA; criterion measure of fatigue and recovery), countermovement jump (CMJ) height, jump efficiency in a multiple rebound jump test (MRJ), 20-m sprint performance, muscle contractile properties, serum concentrations of creatinkinase (CK), c-reactive protein (CRP) and urea as well as perceived muscle soreness (DOMS) were measured pre and post the training program as well as after 72 h of recovery. Results Following the microcycle significant changes (p < 0.05) in RSA as well as in CMJ and MRJ performance could be observed, showing a decline (%Δ ± 90% confidence limits, ES = effect size; RSA: -3.8 ± 1.0, ES = -1.51; CMJ: 8.4 ± 2.9, ES = -1.35; MRJ: 17.4 ± 4.5, ES = -1.60) and a return to baseline level (RSA: 2.8 ± 2.6, ES = 0.53; CMJ: 4.1 ± 2.9, ES = 0.68; MRJ: 6.5 ± 4.5, ES = 0.63) after 72 h of recovery. Athletes also demonstrated significant changes (p < 0.05) in muscle contractile properties, CK, and DOMS following the training program and after the recovery period. In contrast, CRP and urea remained unchanged throughout the study. Further analysis revealed that the accuracy of markers for assessment of fatigue and recovery in comparison to RSA derived from a contingency table was insufficient. Multiple regression analysis also showed no correlations between changes in RSA and any of the markers. Conclusions Mean changes in measures of neuromuscular function, CK and DOMS are related to HIIT induced fatigue and subsequent recovery. However, low accuracy of a single or combined use of these markers requires the verification of their applicability on an individual basis.

The development of peripheral fatigue and short‐term recovery during self‐paced high‐intensity exercise

Type of study: non-rct experimental

Number of citations: 184

Year: 2013

Authors: Christian Froyd, G. Millet, T. Noakes

Journal: The Journal of Physiology

Journal ranking: Q1

Key takeaways: Muscle fatigue develops during self-paced high-intensity exercise within the first 40%, with substantial recovery occurring within 1–2 minutes after exercise termination.

Abstract: In this study we describe the time course of fatigue development during and after an intense bout of self‐paced, high‐intensity dynamic exercise using various electrical stimulation parameters to assess neuromuscular function (NMF) changes. Most of the decrease in muscle function occurs within the first 40% of the exercise bout, and substantial recovery in muscle function occurs within 1–2 min after exercise termination. Decreases in muscle function varied greatly with different methods of stimulation, suggesting that the extent to which muscle fatigue is documented during exercise depends upon NMF assessment methodology. Measurements of muscle function must be performed as soon as possible after exercise termination, and previous studies may have underestimated the extent to which muscle fatigue develops during exercise.

Performance Adaptations to Intensified Training in Top-Level Football

Type of study: literature review

Number of citations: 50

Year: 2022

Authors: M. Hostrup, J. Bangsbo

Journal: Sports Medicine (Auckland, N.z.)

Journal ranking: Q1

Key takeaways: Intensified training periods can enhance performance in elite football players during late preparation and competitive season, with benefits varying depending on training composition and prescription.

Abstract: Because physical demands are surging in football (soccer, USA), clubs are more and more seeking players who have a high capacity to perform repeated intense exercise. High-intensity interval training (HIIT), comprising exercise performed at intensities near or exceeding the capacity of aerobic energy systems, effectively enhances the physical conditioning of players. But given that HIIT imposes high loads, it increases the risk of overload-associated match performance decline and injury. This makes some coaches inclined to conduct HIIT in the weeks leading up to the season and during the season. Therefore, the challenge is how to optimize and dose HIIT during these phases, as they can be decisive. Studies have highlighted the utility of conducting periods of intensified training to overcome the risk of overload while at the same time enhancing performance. During intensified training periods of typically a few weeks, intensity is increased by enlarging the amount of HIIT, for example, aerobic high-intensity training or speed endurance training, while volume at low-to-moderate intensity is significantly reduced. The outcome depends on training composition and prescription—most notably, intensity and duration of bouts and recovery. When work intervals are prescribed for a few minutes at intensities > 90% heart rate max (i.e., aerobic high-intensity training), then beneficial adaptations pertaining to aerobic power and capacity are apparent. But when work intervals are conducted at much higher intensities, as all-out efforts or sprinting of typically 10- to 40-s duration with longer recovery periods (i.e., speed endurance training), beneficial adaptations pertaining to anaerobic energy systems, ion handling, and fatigue resilience are commonly observed. In this review, we discuss the utility of conducting intensified training periods to enhance performance in elite football players during the late preparation phase and competitive season.

Preventing overtraining in athletes in high‐intensity sports and stress/recovery monitoring

Type of study:

Number of citations: 520

Year: 2010

Authors: M. Kellmann

Journal: Scandinavian Journal of Medicine & Science in Sports

Journal ranking: Q1

Key takeaways: Elite athletes need effective recovery and stress monitoring tools to avoid overtraining and maximize training quality, ultimately determining their sporting success.

Abstract: In sports, the importance of optimizing the recovery–stress state is critical. Effective recovery from intense training loads often faced by elite athletes can often determine sporting success or failure. In recent decades, athletes, coaches, and sport scientists have been keen to find creative, new methods for improving the quality and quantity of training for athletes. These efforts have consistently faced barriers, including overtraining, fatigue, injury, illness, and burnout. Physiological and psychological limits dictate a need for research that addresses the avoidance of overtraining, maximizes recovery, and successfully negotiates the fine line between high and excessive training loads. Monitoring instruments like the Recovery–Stress Questionnaire for Athletes can assist with this research by providing a tool to assess their perceived state of recovery. This article will highlight the importance of recovery for elite athletes and provide an overview of monitoring instruments.

Mechanisms of muscle fatigue in intense exercise.

Type of study:

Number of citations: 333

Year: 1997

Authors: H. Green

Journal: Journal of sports sciences

Journal ranking: Q1

Key takeaways: Intense exercise leads to muscle fatigue due to increased ATP utilization, metabolic by-products, and depletion of intracellular glycogen, with potential for increased fatigue resistance through adaptive training programs.

Abstract: The manifestations of fatigue, as observed by reductions in the ability to produce a given force or power, are readily apparent soon after the initiation of intense activity. Moreover, following the activity, a sustained weakness may persist for days or even weeks. The mechanisms responsible for the impairment in performance are various, given the severe strain imposed on the multiple organ systems, tissues and cells by the activity. At the level of the muscle cell, ATP utilization is dramatically accelerated in an attempt to satisfy the energy requirements of the major processes involved in excitation and contraction namely sarcolemmal Na+/K+ exchange, sarcoplasmic reticulum Ca2+ sequestration and actomyosin cycling. In an attempt to maintain ATP levels, high-energy phosphate transfer, glycolysis and oxidative phosphorylation are recruited. With intense activity, ATP production rates are unable to match ATP utilization rates, and reductions in ATP occur accompanied by accumulation of a range of metabolic by-products such as hydrogen ions, inorganic phosphate, AMP, ADP and IMP. Selective by-products are believed to disturb Na+/K+ balance, Ca2+ cycling and actomyosin interaction, resulting in fatigue. Cessation of the activity and normalization of cellular energy potential results in a rapid recovery of force. This type of fatigue is often referred to as metabolic. Repeated bouts of high-intensity activity can also result in depletion of the intracellular substrate, glycogen. Since glycogen is the fundamental fuel used to sustain both glycolysis and oxidative phosphorylation, fatigue is readily apparent as cellular resources are exhausted. Intense activity can also result in non-metabolic fatigue and weakness as a consequence of disruption in internal structures, mediated by the high force levels. This type of impairment is most conspicuous following eccentric muscle activity; it is characterized by myofibrillar disorientation and damage to the cytoskeletal framework in the absence of any metabolic disturbance. The specific mechanisms by which the high force levels promote muscle damage and the degree to which the damage can be exacerbated by the metabolic effects of the exercise remain uncertain. Given the intense nature of the activity and the need for extensive, high-frequency recruitment of muscle fibres and motor units in a range of synergistic muscles, there is limited opportunity for compensatory strategies to enable performance to be sustained. Increased fatigue resistance would appear to depend on carefully planned programmes designed to adapt the excitation and contraction processes, the cytoskeleton and the metabolic systems, not only to tolerate but also to minimize the changes in the intracellular environment that are caused by the intense activity.

Recovery of central and peripheral neuromuscular fatigue after exercise.

Type of study: literature review

Number of citations: 221

Year: 2017

Authors: T. Carroll, Janet L. Taylor, S. Gandevia

Journal: Journal of applied physiology

Journal ranking: Q1

Key takeaways: Recovery of voluntary force generating capacity after exercise varies, with brief high-intensity exercise showing rapid recovery and long-duration exercise showing partial recovery.

Abstract: Sustained physical exercise leads to a reduced capacity to produce voluntary force that typically outlasts the exercise bout. This 'fatigue' can be due both to impaired muscle function, termed 'peripheral fatigue,' and a reduction in the capacity of the central nervous system to activate muscles, termed 'central fatigue.' In this review we consider the factors that determine the recovery of voluntary force generating capacity after various types of exercise. After brief, high-intensity exercise there is typically a rapid restitution of force that is due to recovery of central fatigue (typically within 2 min) and aspects of peripheral fatigue associated with excitation-contraction coupling and reperfusion of muscles (typically within 3-5 min). Complete recovery of muscle function may be incomplete for some hours, however, due to prolonged impairment in intracellular Ca2+ release or sensitivity. After low-intensity exercise of long duration, voluntary force typically shows rapid, partial, recovery within the first few minutes, due largely to recovery of the central, neural component. However, the ability to voluntarily activate muscles may not recover completely within 30 min after exercise. Recovery of peripheral fatigue contributes comparatively little to the fast initial force restitution and is typically incomplete for at least 20-30 min. Work remains to identify what factors underlie the prolonged central fatigue that usually accompanies long-duration single joint and locomotor exercise and to document how the time course of neuromuscular recovery is affected by exercise intensity and duration in locomotor exercise. Such information could be useful to enhance rehabilitation and sports performance.

FEATURES OF FATIGUE AND RECOVERY OF ATHLETES

Type of study:

Number of citations: 2

Year: 2023

Authors: Adilbekov Taxir Tuxtaevich

Journal: American Journal Of Biomedical Science &amp; Pharmaceutical Innovation

Journal ranking: brak

Key takeaways: Understanding the complex mechanisms of fatigue and recovery in athletes is crucial for optimizing training strategies, preventing overtraining, and enhancing performance in various sports disciplines.

Abstract: This article delves into the multifaceted features of fatigue and recovery in athletes, exploring the intricate mechanisms and patterns that characterize these physiological processes. Fatigue, an inevitable consequence of intense physical exertion, involves a complex interplay of central and peripheral factors impactingneuromuscular function, metabolic pathways, and hormonal responses. Conversely, recovery constitutes a dynamic restoration phase, encompassing neural, metabolic, and immune processes aimed at reinstating homeostasis. Understanding the features of fatigue and recovery in athletes is pivotal for optimizing training strategies, preventing overtraining, and enhancing performance. This review elucidates the distinctive characteristics, temporal patterns, and influential factors underlying fatigue and recovery in athletes across various sports disciplines.

Effect of Repeated Active Recovery During a High-Intensity Interval-Training Shock Microcycle on Markers of Fatigue.

Type of study:

Number of citations: 30

Year: 2016

Authors: T. Wiewelhove, C. Raeder, T. Meyer, M. Kellmann, M. Pfeiffer, A. Ferrauti

Journal: International journal of sports physiology and performance

Journal ranking: Q1

Key takeaways: Repeated use of moderate jogging after each training session during an HIT shock microcycle did not affect exercise-induced fatigue markers.

Abstract: PURPOSE To investigate the effect of repeated use of active recovery during a 4-d shock microcycle with 7 high-intensity interval-training (HIT) sessions on markers of fatigue. METHODS Eight elite male junior tennis players (age 15.1 ± 1.4 y) with an international ranking between 59 and 907 (International Tennis Federation) participated in this study. After each training session, they completed 15 min of either moderate jogging (active recovery [ACT]) or passive recovery (PAS) with a crossover design, which was interrupted by a 4-mo washout period. Countermovement-jump (CMJ) height, serum concentration of creatine kinase (CK), delayed-onset muscle soreness (DOMS), and perceived recovery and stress (Short Recovery and Stress Scale) were measured 24 h before and 24 h after the training program. RESULTS The HIT shock microcycle induced a large decrease in CMJ performance (ACT: effect size [ES] = -1.39, P < .05; PAS: ES = -1.42, P < .05) and perceived recovery (ACT: ES = -1.79, P < .05; PAS: ES = -2.39, P < .05), as well as a moderate to large increase in CK levels (ACT: ES = 0.76, P > .05; PAS: ES = 0.81, P >.05), DOMS (ACT: ES = 2.02, P < .05; PAS: ES = 2.17, P < .05), and perceived stress (ACT: ES = 1.98, P < .05; PAS: ES = 3.06, P < .05), compared with the values before the intervention. However, no significant recovery intervention × time interactions or meaningful differences in changes were noted in any of the markers between ACT and PAS. CONCLUSIONS Repeated use of individualized ACT, consisting of 15 min of moderate jogging, after finishing each training session during an HIT shock microcycle did not affect exercise-induced fatigue.

Cold water immersion and recovery from strenuous exercise: a meta-analysis

Type of study: meta-analysis

Number of citations: 289

Year: 2011

Authors: J. Leeder, C. Gissane, K. van Someren, W. Gregson, G. Howatson

Journal: British Journal of Sports Medicine

Journal ranking: Q1

Key takeaways: Cold water immersion can effectively improve recovery from strenuous exercise, potentially enhancing performance in elite athletes.

Abstract: Elite-level athletic training and competition is accompanied by the recovery of a series of physiological stressors. The physiological stress will vary considerably depending upon the specific exercise type, duration and intensity and also on the athletes' familiarisation to the exercise insult. It is well documented that when the exercise stress incorporates a novel eccentric component or the exercise is of considerable intensity or duration,1 athletes will likely experience numerous signs and symptoms of fatigue and cellular disturbance that have the potential to reduce performance. Physiological stress induced by intense exercise is associated with energy substrate depletion, hyperthermia, mechanical muscle damage, oxidative stress, inflammation and nervous system fatigue. The resulting symptoms manifest as reduced performance potential, likely due to increased muscle soreness and decreased muscle function,2 disturbed muscle position sense and reaction time3 as well as increased stiffness and swelling that can last for several days.4 The aetiology of reduced performance potential will vary depending upon the exact physiological stress being recovered from. For example, eccentric exercise is associated with a large mechanical stress and relatively low metabolic cost,5 whereas intermittent sprint exercise may involve both a large mechanical stress and a heightened metabolic cost.6 It is possible that the underlying time course of recovery between different exercise stressors is different, and this consequently may influence how recovery strategies could be implemented. For the purpose of this review, exercise will be subdivided into two categories: ‘eccentric exercise’ that refers to the stress caused from exercise incorporating high mechanical stress (eg, eccentric contractions) and ‘high-intensity exercise’ that refers to stress caused from exercise with a high metabolic cost as well as some elements of eccentric muscle contractions (eg, repeat sprint sports). Given the potential for physiological stress to compromise training and/or competition performance, there has been …

Exercise Intensity and Recovery: Biomarkers of Injury, Inflammation, and Oxidative Stress

Type of study: non-rct experimental

Number of citations: 143

Year: 2016

Authors: A. Bessa, V. N. Oliveira, Guilherme G. Agostini, R. J. Oliveira, A. C. Oliveira, Gillian E. White, G. Wells, D. N. Teixeira, F. Espíndola

Journal: Journal of Strength and Conditioning Research

Journal ranking: Q1

Key takeaways: High-intensity exercise in elite athletes generates localized inflammation in skeletal muscle, but using biomarkers can improve coaches' ability to assess recovery and set training intensities.

Abstract: Abstract Bessa, AL, Oliveira, VN, Agostini, GG, Oliveira, RJS, Oliveira, ACS, White, GE, Wells, GD, Teixeira, DNS, and Espindola, FS. Exercise intensity and recovery: Biomarkers of injury, inflammation, and oxidative stress. J Strength Cond Res 30(2): 311–319, 2016—Biomarkers of inflammation, muscle damage, and oxidative stress after high-intensity exercise have been described previously; however, further understanding of their role in the postexercise recovery period is necessary. Because these markers have been implicated in cell signaling, they may be specifically related to the training adaptations induced by high-intensity exercise. Thus, a clear model showing their responses to exercise may be useful in characterizing the relative recovery status of an athlete. The purpose of this study was twofold: (a) to investigate the time course of markers of muscle damage and inflammation in the blood from 3 to 72 hours after combined training exercises and (b) to investigate indicators of oxidative stress and damage associated with increased reactive oxygen species production during high-intensity exercise in elite athletes. Nineteen male athletes performed a combination of high-intensity aerobic and anaerobic training exercises. Samples were acquired immediately before and at 3, 6, 12, 24, 48, and 72 hours after exercise. The appearance and clearance of creatine kinase and lactate dehydrogenase in the blood occurred faster than previous studies have reported. The neutrophil/lymphocyte ratio summarizes the mobilization of 2 leukocyte subpopulations in a single marker and may be used to predict the end of the postexercise recovery period. Further analysis of the immune response using serum cytokines indicated that high-intensity exercise performed by highly trained athletes only generated inflammation that was localized to the skeletal muscle. Biomarkers are not a replacement for performance tests, but when used in conjunction, they may offer a better indication of metabolic recovery status. Therefore, the use of biomarkers can improve a coach's ability to assess the recovery period after an exercise session and to establish the intensity of subsequent training sessions.

Changes in Perceived Exertion, Well-Being, and Recovery During Specific Judo Training: Impact of Training Period and Exercise Modality

Type of study: rct

Number of citations: 20

Year: 2020

Authors: I. Ouergui, L. Ardigò, O. Selmi, D. Levitt, H. Chtourou, A. Bouassida, E. Bouhlel, E. Franchini

Journal: Frontiers in Physiology

Journal ranking: Q2

Key takeaways: Specific judo training modalities (Randori and Uchi-komi) during intense training and a 12-day tapering period improve well-being and recovery in judo athletes.

Abstract: The present study investigated the effect of intense and tapering training periods using different exercise modalities (i.e., Randori – grip dispute practice without throwing technique, Uchi-komi – technique repetition training, and sprinting) on rating of perceived exertion (RPE), well-being indices, recovery state, and physical enjoyment in judo athletes. Sixty-one adolescent male and female judo athletes (age: 15 ± 1 years) were randomly assigned to one of three experimental or one control groups. Experimental groups (Randori, Uchi-komi, and running) trained four times per week for 4 weeks of intense training (in addition to their usual technical-tactical judo training; control group underwent only such a training) followed by 12 days of tapering. RPE, well-being indices [i.e., sleep, stress, fatigue, and delayed onset muscle soreness (DOMS)], total quality of recovery (TQR), and physical enjoyment were measured every session. RPE, sleep, stress, fatigue, DOMS, Hooper index (HI; sum of wellbeing indices), and TQR were lower in the tapering compared with the intensified training period (P < 0.001). Moreover, the running group showed better values for sleep (P < 0.001), stress (P < 0.001), fatigue (P = 0.006), DOMS (P < 0.001), and HI (P < 0.001) in comparison with the other training groups, indicating a more negative state of wellbeing. The Randori and Uchi-komi groups showed higher values for TQR and physical enjoyment (both P < 0.001) than the running group, whereas RPE was lower in the control compared with all training groups (P < 0.001). Coaches should use more specific training modalities (i.e., Randori and Uchi-komi) during intensified training and should monitor well-being indices, RPE, and TQR during training periods. Moreover, for all variables, 12 days tapering period are beneficial for improving wellbeing and recovery after 4 weeks of intense training.

Limitations in intense exercise performance of athletes – effect of speed endurance training on ion handling and fatigue development

Type of study: literature review

Number of citations: 84

Year: 2017

Authors: M. Hostrup, J. Bangsbo

Journal: The Journal of Physiology

Journal ranking: Q1

Key takeaways: Regular speed endurance training (SET) enhances intense exercise performance in highly trained individuals, primarily due to adaptations in muscle ion handling.

Abstract: Mechanisms underlying fatigue development and limitations for performance during intense exercise have been intensively studied during the past couple of decades. Fatigue development may involve several interacting factors and depends on type of exercise undertaken and training level of the individual. Intense exercise (½–6 min) causes major ionic perturbations (Ca2+, Cl−, H+, K+, lactate− and Na+) that may reduce sarcolemmal excitability, Ca2+ release and force production of skeletal muscle. Maintenance of ion homeostasis is thus essential to sustain force production and power output during intense exercise. Regular speed endurance training (SET), i.e. exercise performed at intensities above that corresponding to maximum oxygen consumption ( V̇O2, max ), enhances intense exercise performance. However, most of the studies that have provided mechanistic insight into the beneficial effects of SET have been conducted in untrained and recreationally active individuals, making extrapolation towards athletes’ performance difficult. Nevertheless, recent studies indicate that only a few weeks of SET enhances intense exercise performance in highly trained individuals. In these studies, the enhanced performance was not associated with changes in V̇O2, max and muscle oxidative capacity, but rather with adaptations in muscle ion handling, including lowered interstitial concentrations of K+ during and in recovery from intense exercise, improved lactate−–H+ transport and H+ regulation, and enhanced Ca2+ release function. The purpose of this Topical Review is to provide an overview of the effect of SET and to discuss potential mechanisms underlying enhancements in performance induced by SET in already well‐trained individuals with special emphasis on ion handling in skeletal muscle.

Recovery of the autonomic nervous system following football training among division I collegiate football athletes: The influence of intensity and time

Type of study: non-rct experimental

Number of citations: 10

Year: 2023

Authors: S. Wittels, Eric Renaghan, M. Wishon, Harrison L. Wittels Esq, Stephanie Chong, E. D. Wittels, S. Hendricks, Dustin Hecocks, Kyle Bellamy, Joe Girardi, Stephen J Lee, Samantha M McDonald, Luis A. Feigenbaum

Journal: Heliyon

Journal ranking: Q1

Key takeaways: Prolonged high intensity exercise impairs autonomic nervous system recovery and function in Division I football athletes for more than 24 hours, suggesting shorter bouts and longer recovery periods.

The Sleep and Recovery Practices of Athletes

Type of study: non-rct observational study

Number of citations: 55

Year: 2021

Authors: Ronan J. Doherty, S. Madigan, A. Nevill, G. Warrington, J. Ellis

Journal: Nutrients

Journal ranking: Q1

Key takeaways: Athletes, both elite and sub-elite, experience poor sleep and high levels of fatigue, stress, and pain, highlighting the need for individualized support and education on sleep and recovery practices.

Abstract: Background: Athletes maintain a balance between stress and recovery and adopt recovery modalities that manage fatigue and enhance recovery and performance. Optimal TST is subject to individual variance. However, 7–9 h sleep is recommended for adults, while elite athletes may require more quality sleep than non-athletes. Methods: A total of 338 (elite n = 115, 74 males and 41 females, aged 23.44 ± 4.91 years; and sub-elite n = 223, 129 males and 94 females aged 25.71 ± 6.27) athletes were recruited from a variety of team and individual sports to complete a battery of previously validated and reliable widely used questionnaires assessing sleep, recovery and nutritional practices. Results: Poor sleep was reported by both the elite and sub-elite athlete groups (i.e., global PSQI score ≥5—elite 64% [n = 74]; sub-elite 65% [n = 146]) and there was a significant difference in sport-specific recovery practices (3.22 ± 0.90 vs. 2.91 ± 0.90; p < 0.001). Relatively high levels of fatigue (2.52 ± 1.32), stress (1.7 ± 1.31) and pain (50%, n = 169) were reported in both groups. A range of supplements were used regularly by athletes in both groups; indeed, whey (elite n = 22 and sub-elite n = 48) was the most commonly used recovery supplement in both groups. Higher alcohol consumption was observed in the sub-elite athletes (12%, n = 26) and they tended to consume more units of alcohol per drinking bout. Conclusion: There is a need for athletes to receive individualised support and education regarding their sleep and recovery practices.

Muscular fatigue in response to different modalities of CrossFit sessions

Type of study: non-rct experimental

Number of citations: 91

Year: 2017

Authors: J. Maté-Muñoz, J. H. Lougedo, Manuel Barba, Pablo García-Fernández, M. Garnacho-Castaño, R. Domínguez

Journal: PLoS ONE

Journal ranking: Q1

Key takeaways: CrossFit gymnastics and weightlifting sessions induce muscular fatigue, while metabolic conditioning sessions allow for recovery due to rest intervals.

Abstract: Background CrossFit is a new strength and conditioning regimen involving short intense daily workouts called workouts of the day (WOD). This study assesses muscular fatigue levels induced by the three modalities of CrossFit WOD; gymnastics (G), metabolic conditioning (M) and weightlifting (W). Material and methods 34 healthy subjects undertook three WOD (one per week): a G WOD consisting of completing the highest number of sets of 5 pull-ups, 10 push-ups and 15 air squats in 20 min; an M WOD, in which the maximum number of double skipping rope jumps was executed in 8 sets (20 s), resting (10 s) between sets; and finally, a W WOD in which the maximum number of power cleans was executed in 5 min, lifting a load equivalent to 40% of the individual's 1RM. Before and after each WOD, blood lactate concentrations were measured. Also, before, during, and after each WOD, muscular fatigue was assessed in a countermovement jump test (CMJ). Results Significant reductions were produced in the mechanical variables jump height, average power and maximum velocity in response to G; and in jump height, mean and peak power, maximum velocity and maximum force in response to W (P<0.01). However, in M, significant reductions in mechanical variables were observed between pre- and mid session (after sets 2, 4, 6 and 8), but not between pre- and post session. Conclusions Muscular fatigue, reflected by reduced CMJ variables, was produced following the G and W sessions, while recovery of this fatigue was observed at the end of M, likely attributable to rest intervals allowing for the recovery of phosphocreatine stores. Our findings also suggest that the high intensity and volume of exercise in G and W WODs could lead to reduced muscular-tendon stiffness causing a loss of jump ability, related here to a longer isometric phase during the CMJ.

Impact of tapering and proactive recovery on young elite rugby union players’ repeated high intensity effort ability

Type of study: non-rct experimental

Number of citations: 9

Year: 2021

Authors: Adrien Vachon, N. Berryman, I. Mujika, Jean-Baptiste Paquet, F. Sauvet, L. Bosquet

Journal: Biology of Sport

Journal ranking: Q1

Key takeaways: Tapering and proactive recovery in elite rugby union players did not improve repeated high intensity effort ability, but improved acute fatigue, likely due to pre-taper fatigue and poor sleep quality.

Abstract: To assess the effects of a taper combined with proactive recovery on the repeated high intensity effort (RHIE) of elite rugby union players, and the possible interaction of pre-taper fatigue and sleep. Eighteen players performed a 3-week intensive training block followed by a 7-day exponential taper combined with a multicomponent recovery strategy. Following the intervention, players were divided into 3 groups (Normal Training: NT, Acute Fatigue: AF or Functional Overreaching: F-OR) based on their readiness to perform prior to the taper. Total sprint time [TST], percentage decrement [%D] and the number of sprints ≥90% of the best [N90] were analyzed to assess performance during a RHIE test. Subjective sleep quality was assessed through the Pittsburg Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS). No improvement in TST was reported in either NT or F-OR after the taper, whereas AF tended to improve (-1.58 ± 1.95%; p > 0.05; g = -0.20). F-OR players reported baseline PSQI and ESS indicative of sleep disturbance (6.2 ± 2.2 and 10.6 ± 5.4, respectively). AF displayed a small impairment in PSQI during intensive training (11.5 ± 80.6%; p > 0.05; g = 0.20), which was reversed following the taper (-34.6 ± 62.1%; p > 0.05; g = -0.73). Pre-taper fatigue precluded the expected performance benefits of the combined taper and recovery intervention, likely associated with a lack of strictly controlled intensive training block. Poor sleep quality before the intensive training period appeared to predispose the players to developing functional overreaching.

Impact of Blood Flow Restriction Exercise on Muscle Fatigue Development and Recovery

Type of study: non-rct experimental

Number of citations: 79

Year: 2017

Authors: F. Husmann, T. Mittlmeier, S. Bruhn, V. Zschorlich, M. Behrens

Journal: Medicine & Science in Sports & Exercise

Journal ranking: Q1

Key takeaways: Blood flow restriction during low-intensity exercise increases muscle fatigue, but this effect diminishes within 2 minutes of reperfusion.

Abstract: PurposeThe present study was designed to provide mechanistic insight into the time course and etiology of muscle fatigue development and recovery during and after low-intensity exercise when it is combined with blood flow restriction (BFR). MethodsSeventeen resistance-trained males completed four sets of low-intensity isotonic resistance exercise under two experimental conditions: knee extension exercise (i) with BFR and (ii) without BFR (CON). Neuromuscular tests were performed before, during (immediately after each set of knee extension exercise), and 1, 2, 4, and 8 min after each experimental condition. Maximal voluntary torque, quadriceps twitch torque in response to paired electrical stimuli at 10 Hz (PS10) and 100 Hz (PS100), PS10·PS100−1 ratio as an index of low-frequency fatigue, and voluntary activation were measured under isometric conditions. Perceptual and EMG data were recorded during each exercise condition. ResultsAfter the first set of exercise, BFR induced significantly greater reductions in maximal voluntary torque, PS100, and PS10·PS100−1 ratio compared with CON. These parameters progressively declined throughout the BFR protocol but recovered substantially within 2 min postexercise when blood flow was restored. Neither a progressive decline in the course of the exercise protocol nor a substantial recovery of these parameters occurred during and after CON. Only at exercise termination, voluntary activation differed significantly between BFR and CON with greater reductions during BFR. ConclusionAt the early stage of exercise, BFR exacerbated the development of muscle fatigue mainly due to a pronounced impairment in contractile function. Despite the high level of muscle fatigue during BFR exercise, the effect of BFR on muscle fatigue was diminished after 2 min of reperfusion, suggesting that BFR has a strong but short-lasting effect on neuromuscular function.

Overtraining in Resistance Exercise: An Exploratory Systematic Review and Methodological Appraisal of the Literature

Type of study: systematic review

Number of citations: 48

Year: 2019

Authors: C. Grandou, L. Wallace, F. Impellizzeri, N. Allen, A. Coutts

Journal: Sports Medicine

Journal ranking: Q1

Key takeaways: Overtraining in resistance exercise may result from frequent high-intensity training, but no reliable marker other than sustained performance decrease has been established.

Abstract: BackgroundThe balance between training stress and recovery is important for inducing adaptations to improve athletic performance. However, continuously high training loads with insufficient recovery may cause fatigue to accumulate and result in overtraining. A comprehensive systematic review is required to collate overtraining literature and improve the current understanding of the mechanisms underlying functional overreaching (FOR), non-functional overreaching (NFOR) and the overtraining syndrome (OTS) in resistance training.ObjectiveThe objective of this systematic review was to establish markers of overtraining and elucidate the mechanisms underlying maladaptive resistance training conditions. Furthermore, this review aims to critically evaluate the methodological approaches of the overtraining literature.MethodsA systematic literature search was performed on PubMed, Web of Science and SPORTDiscus to identify studies up to June 2019. Electronic databases were searched using terms related to resistance training and overtraining. Records were included if they attempted to induce a state of overreaching or overtraining through resistance exercise in healthy participants.ResultsA total of 22 studies were selected for review. Among these studies, eight resulted in decrements in performance and measured changes in performance during a follow-up period. There were four studies that reported decrease in performance yet failed to implement follow-up measures. A total of 10 studies reported no decline in performance. Overall, a lack of standardisation in methodology (follow-up performance testing) and diagnostic criteria prevents consistent determination of FOR, NFOR and OTS in resistance training.ConclusionsFew studies have appropriately established FOR, NFOR or OTS in resistance training. Overtraining may be related to frequent high-intensity and monotonous resistance training. However, no marker other than a sustained decrease in performance has been established as a reliable indicator of overtraining in resistance exercise.RegistrationThis systematic review was registered on the Open Science Framework (https://osf.io/) (https://doi.org/10.17605/osf.io/5bmsp).