Flexibility training (stretching)

The effects of chronic stretch training on musculoskeletal pain.

Type of study: systematic review

Number of citations: 0

Year: 2025

Authors: Andreas Konrad, Masatoshi Nakamura, Mahta Sardroodian, Nazanin Aboozari, Saman Hadjizedah Anvar, D. Behm

Journal: European journal of applied physiology

Journal ranking: Q1

Key takeaways: Stretching can effectively reduce musculoskeletal pain by enhancing range of motion and reducing muscle stiffness, potentially easing nerve pressure and lowering muscle spindle activity.

Abstract: Abstract Purpose One of the primary mechanisms for the increase in range of motion following stretching is an increase in pain/stretch tolerance. However, it remains unclear whether stretching can reduce pain in patients suffering from musculoskeletal pain. Therefore, the purpose of this systematic review was to investigate whether chronic stretch training can decrease pain in patients suffering from musculoskeletal pain. Methods In our search, we included three databases (PubMed, Scopus, and Web of Science) and after removing duplicates, screened 797 papers. Six papers were found to be eligible for this review. The inclusion criteria were controlled or randomized controlled trials that involved any type of chronic stretch training with participants experiencing musculoskeletal pain and where at least one pain output parameter was reported (e.g. visual analogue scale). Results Of the six studies reviewed, four focused on the effects of stretching interventions on pain in patients, while the other two examined pain prevalence during the stretching period. The interventions lasted between 4 weeks and 6 months and involved either static or dynamic stretching techniques with in total 658 participants. Five of the six studies reported a significant decrease in pain scores or a reduction in the prevalence or severity of pain following the observation period. Conclusion The findings indicate that stretching can alleviate pain by enhancing range of motion and reducing muscle stiffness, which may ease nerve pressure and lower muscle spindle activity. Although results were somewhat mixed, the evidence overall supports stretching as an effective intervention for relieving musculoskeletal pain.

Effects of daily static stretch training over 6 weeks on maximal strength, muscle thickness, contraction properties, and flexibility

Type of study: rct

Number of citations: 15

Year: 2023

Authors: Tim Wohlann, Konstantin Warneke, M. Hillebrecht, A. Petersmann, A. Ferrauti, S. Schiemann

Journal: Frontiers in Sports and Active Living

Journal ranking: Q1

Key takeaways: Daily static stretch training for 5 minutes over 6 weeks increases maximal strength and flexibility, but does not significantly change muscle stiffness or contraction time.

Abstract: Purpose Static stretch training (SST) with long stretching durations seems to be sufficient to increase flexibility, maximum strength (MSt) and muscle thickness (MTh). However, changes in contraction properties and effects on muscle damage remain unclear. Consequently, the objective of the study was to investigate the effects of a 6-week self-performed SST on MSt, MTh, contractile properties, flexibility, and acute response of creatine kinase (CK) 3 days after SST. Methods Forty-four participants were divided into a control (CG, n = 22) and an intervention group (IG, n = 22), who performed a daily SST for 5 min for the lower limb muscle group. While isometric MSt was measured in leg press, MTh was examined via sonography and flexibility by functional tests. Muscle stiffness and contraction time were measured by tensiomyography on the rectus femoris. Additionally, capillary blood samples were taken in the pretest and in the first 3 days after starting SST to measure CK. Results A significant increase was found for MSt (p < 0.001, η2 = 0.195) and flexibility in all functional tests (p < 0.001, η2 > 0.310). Scheffé post hoc test did not show significant differences between the rectus femoris muscle inter- and intragroup comparisons for MTh nor for muscle stiffness and contraction time (p > 0.05, η2 < 0.100). Moreover, CK was not significantly different between IG and CG with p > 0.05, η2 = 0.032. Discussion In conclusion, the increase in MSt cannot be exclusively explained by muscular hypertrophy or the increased CK-related repair mechanism after acute stretching. Rather, neuronal adaptations have to be considered. Furthermore, daily 5-min SST over 6 weeks does not seem sufficient to change muscle stiffness or contraction time. Increases in flexibility tests could be attributed to a stretch-induced change in the muscle–tendon complex.

Discussing Conflicting Explanatory Approaches in Flexibility Training Under Consideration of Physiology: A Narrative Review

Type of study: literature review

Number of citations: 6

Year: 2024

Authors: Konstantin Warneke, D. Behm, S. Alizadeh, M. Hillebrecht, Andreas Konrad, Klaus Wirth

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

Journal ranking: Q1

Key takeaways: Flexibility training enhances range of motion through general warm-up effects and mechanical tension applied to greater muscle lengths, rather than solely relying on stretching or foam rolling.

Abstract: Abstract The mechanisms underlying range of motion enhancements via flexibility training discussed in the literature show high heterogeneity in research methodology and study findings. In addition, scientific conclusions are mostly based on functional observations while studies considering the underlying physiology are less common. However, understanding the underlying mechanisms that contribute to an improved range of motion through stretching is crucial for conducting comparable studies with sound designs, optimising training routines and accurately interpreting resulting outcomes. While there seems to be no evidence to attribute acute range of motion increases as well as changes in muscle and tendon stiffness and pain perception specifically to stretching or foam rolling, the role of general warm-up effects is discussed in this paper. Additionally, the role of mechanical tension applied to greater muscle lengths for range of motion improvement will be discussed. Thus, it is suggested that physical training stressors can be seen as external stimuli that control gene expression via the targeted stimulation of transcription factors, leading to structural adaptations due to enhanced protein synthesis. Hence, the possible role of serial sarcomerogenesis in altering pain perception, reducing muscle stiffness and passive torque, or changes in the optimal joint angle for force development is considered as well as alternative interventions with a potential impact on anabolic pathways. As there are limited possibilities to directly measure serial sarcomere number, longitudinal muscle hypertrophy remains without direct evidence. The available literature does not demonstrate the necessity of only using specific flexibility training routines such as stretching to enhance acute or chronic range of motion.

Acute Effects of Dynamic Stretching on Muscle Flexibility and Performance: An Analysis of the Current Literature

Type of study: literature review

Number of citations: 190

Year: 2018

Authors: Jules Opplert, N. Babault

Journal: Sports Medicine

Journal ranking: Q1

Key takeaways: Dynamic stretching positively impacts muscle flexibility and performance, making it a suitable alternative to static stretching for increasing joint range of motion and enhancing force and power.

Abstract: Stretching has long been used in many physical activities to increase range of motion (ROM) around a joint. Stretching also has other acute effects on the neuromuscular system. For instance, significant reductions in maximal voluntary strength, muscle power or evoked contractile properties have been recorded immediately after a single bout of static stretching, raising interest in other stretching modalities. Thus, the effects of dynamic stretching on subsequent muscular performance have been questioned. This review aimed to investigate performance and physiological alterations following dynamic stretching. There is a substantial amount of evidence pointing out the positive effects on ROM and subsequent performance (force, power, sprint and jump). The larger ROM would be mainly attributable to reduced stiffness of the muscle–tendon unit, while the improved muscular performance to temperature and potentiation-related mechanisms caused by the voluntary contraction associated with dynamic stretching. Therefore, if the goal of a warm-up is to increase joint ROM and to enhance muscle force and/or power, dynamic stretching seems to be a suitable alternative to static stretching. Nevertheless, numerous studies reporting no alteration or even performance impairment have highlighted possible mitigating factors (such as stretch duration, amplitude or velocity). Accordingly, ballistic stretching, a form of dynamic stretching with greater velocities, would be less beneficial than controlled dynamic stretching. Notwithstanding, the literature shows that inconsistent description of stretch procedures has been an important deterrent to reaching a clear consensus. In this review, we highlight the need for future studies reporting homogeneous, clearly described stretching protocols, and propose a clarified stretching terminology and methodology.

Chronic effects of stretching on range of motion with consideration of potential moderating variables: A systematic review with meta-analysis

Type of study: meta-analysis

Number of citations: 40

Year: 2023

Authors: A. Konrad, S. Alizadeh, A. Daneshjoo, Saman Hadjizedah Anvar, Andrew Graham, A. Zahiri, R. Goudini, Chris Edwards, Carina Scharf, David G. Behm

Journal: Journal of Sport and Health Science

Journal ranking: Q1

Key takeaways: Stretch training can increase joint range of motion, with proprioceptive neuromuscular facilitation and static stretching producing greater gains than ballistic/dynamic stretching, and females showing higher gains compared to males.

Optimising the Dose of Static Stretching to Improve Flexibility: A Systematic Review, Meta-analysis and Multivariate Meta-regression.

Type of study: meta-analysis

Number of citations: 3

Year: 2024

Authors: Lewis A Ingram, Grant R Tomkinson, N. d'Unienville, Bethany Gower, Sam Gleadhill, Terry Boyle, H. Bennett

Journal: Sports medicine

Journal ranking: Q1

Key takeaways: Static stretching improves flexibility in adults, with maximum benefits observed at 4 minutes per session or 10 minutes per week, and lower flexibility levels lead to greater improvements.

Abstract: BackgroundStatic stretching is widely used to increase flexibility. However, there is no consensus regarding the optimal dosage parameters for increasing flexibility.ObjectivesWe aimed to determine the optimal frequency, intensity and volume to maximise flexibility through static stretching, and to investigate whether this is moderated by muscle group, age, sex, training status and baseline level of flexibility.MethodsSeven databases (CINAHL Complete, Cochrane CENTRAL, Embase, Emcare, MEDLINE, Scopus, and SPORTDiscus) were systematically searched up to June 2024. Randomised and non-randomised controlled trials investigating the effects of a single session (acute) or multiple sessions (chronic) of static stretching on one or more flexibility outcomes (compared to non-stretching passive controls) among adults (aged ≥ 18 years) were included. A multi-level meta-analysis examined the effect of acute and chronic static stretching on flexibility outcomes, while multivariate meta-regression was used to determine the volume at which increases in flexibility were maximised.ResultsData from 189 studies representing 6654 adults (61% male; mean [standard deviation] age = 26.8 ± 11.4 years) were included. We found a moderate positive effect of acute static stretching on flexibility (summary Hedges’ g = 0.63, 95% confidence interval 0.52–0.75, p < 0.001) and a large positive effect of chronic static stretching on flexibility (summary Hedges’ g = 0.96, 95% confidence interval 0.84–1.09, p < 0.001). Neither effect was moderated by stretching intensity, age, sex or training status, or weekly session frequency and intervention length (chronic static stretching only) [p > 0.05]. However, larger improvements were found for adults with poor baseline flexibility compared with adults with average baseline flexibility (p = 0.01). Furthermore, larger improvements in flexibility were found in the hamstrings compared with the spine following acute static stretching (p = 0.04). Improvements in flexibility were maximised by a cumulative stretching volume of 4 min per session (acute) and 10 min per week (chronic).ConclusionsStatic stretching improves flexibility in adults, with no additional benefit observed beyond 4 min per session or 10 min per week. Although intensity, frequency, age, sex and training status do not influence improvements in flexibility, lower flexibility levels are associated with greater improvement following both acute and chronic static stretching. These guidelines for static stretching can be used by coaches and therapists to improve flexibility.Clinical Trial RegistrationPROSPERO CRD42023420168.

Acute and Prolonged Effects of 300 sec of Static, Dynamic, and Combined Stretching on Flexibility and Muscle Force.

Type of study: rct

Number of citations: 9

Year: 2023

Authors: Shingo Matsuo, M. Iwata, M. Miyazaki, Taizan Fukaya, Eiji Yamanaka, Kentaro Nagata, Wakako Tsuchida, Y. Asai, Shigeyuki Suzuki

Journal: Journal of sports science & medicine

Journal ranking: Q1

Key takeaways: 300 seconds of static, dynamic, and combined stretching all improve flexibility and muscle force, but with different acute and prolonged effects.

Abstract: Static stretching (SS), dynamic stretching (DS), and combined stretching (CS; i.e., DS+SS) are commonly performed as warm-up exercises. However, the stretching method with the greatest effect on flexibility and performance remains unclear. This randomized crossover trial examined acute and prolonged effects of SS, DS, and CS on range of motion (ROM), peak passive torque (PPT), passive stiffness, and isometric and concentric muscle forces. Twenty healthy young men performed 300 sec of active SS, DS, or CS (150-sec SS followed by 150-sec DS and 150-sec DS followed by 150-sec SS) of the right knee flexors on four separate days, in random order. Subsequently, we measured ROM, PPT, and passive stiffness during passive knee extension. We also measured maximum voluntary isometric and concentric knee flexion forces and surface electromyographic activities during force measurements immediately before, immediately after, and 20 and 60 min after stretching. All stretching methods significantly increased ROM and PPT, while significantly decreasing isometric knee flexion force (all p < 0.05). These changes lasted 60 min after all stretching methods; the increases in ROM and PPT and the decreases in isometric muscle force were similar. All stretching methods also significantly decreased passive stiffness immediately after stretching (all p < 0.05). Decreases in passive stiffness tended to be longer after CS than after SS or DS. Concentric muscle force was decreased after SS and CS (all p < 0.05). On the other hand, concentric muscle force was unchanged after DS, while the decreases in surface electromyographic activities during concentric force measurements after all stretching methods were similar. Our results suggest that 300 sec of SS, DS, and CS have different acute and prolonged effects on flexibility and muscle force.

Why Flexibility Deserves to Be Further Considered as a Standard Component of Physical Fitness: A Narrative Review of Existing Insights from Static Stretching Study Interventions

Type of study: systematic review

Number of citations: 15

Year: 2023

Authors: Raja Bouguezzi, Senda Sammoud, A. Markov, Y. Negra, H. Chaabène

Journal: Youth

Journal ranking: brak

Key takeaways: Flexibility should remain a standard component of physical fitness due to its positive effects on muscle strength, power, and hypertrophy, and potential injury prevention.

Abstract: The utility of flexibility as a standard component of physical fitness has recently been questioned, sparking a heated debate among scientists. More specifically, it has recently been proposed to retire flexibility as a major component of physical fitness and as a result de-emphasis stretching from exercise prescriptions. The aim of this narrative review was to summarize and discuss the most recent evidence related to the chronic effects of static stretching (SS) on muscle strength, muscle power, muscle hypertrophy, and injury prevention in healthy individuals. A literature search was conducted using the electronic databases PubMed, SPORTDiscus, Web of Science, and Google Scholar up to November 2022. We only considered studies written in English that addressed the chronic effects of SS exercises on flexibility, muscle strength, muscle power, muscle hypertrophy, or injury prevention in healthy individuals. With reference to the existing knowledge, we concluded that flexibility deserves to be further considered as a standard component of physical fitness. This is based on the findings that in addition to flexibility, long-term SS training induces positive effects on muscle strength, muscle power, and muscle hypertrophy, irrespective of age and sex. There are also indications that long-term SS training could mitigate the risk of injury, although this remains a debatable topic. Furthermore, promising evidence shows that combining resistance training with SS exercises constitutes an effective approach benefiting muscle strength and hypertrophy more than resistance training alone. In conclusion, we would not support the recent suggestion that flexibility should be retired as a standard component of physical fitness and we would advocate for a continuous emphasis on the prescription of stretching exercises.

Effects of stretching in a pilates program on musculoskeletal fitness: a randomized clinical trial

Type of study: rct

Number of citations: 2

Year: 2024

Authors: Alex Lopes Dos Reis, Laís Campos de Oliveira, Raphael Gonçalves de Oliveira

Journal: BMC Sports Science, Medicine and Rehabilitation

Journal ranking: Q2

Key takeaways: Stretching exercises in a Pilates program improve flexibility and reduce the chances of musculoskeletal pain and discomfort in young women, without impairing strength, vertical jump height, or muscular endurance.

Abstract: Abstract Background The scientific literature questions the impact of stretching exercises performed immediately before muscle strengthening exercises on different components of musculoskeletal physical fitness. Pilates is a physical exercise modality that typically uses stretching exercises preceding muscle-strengthening exercises. However, no studies have investigated the effects of stretching in a Pilates program on components of musculoskeletal fitness. The aim of the present study was to verify the effects of stretching in a Pilates exercise program on flexibility, strength, vertical jump height and muscular endurance. Methods Thirty-two sedentary young women were randomized into two groups: traditional Pilates (TP), who performed flexibility and muscle strengthening exercises ( n = 16), and nontraditional Pilates (NTP), who only performed muscle-strengthening exercises ( n = 16). Sessions took place 3 times a week for 8 weeks. The following tests were performed pre- and postintervention: 10-RM knee extensors, vertical jump, handgrip, 1-min sit-ups, Sorensen and sit-and-reach. The occurrence of adverse events was recorded throughout the intervention and compared between groups using odds ratio (OR). To compare the results of motor tests between groups, ANCOVA or Mann‒Whitney U test was used for parametric and nonparametric data, respectively. The data were analyzed by intention-to-treat. Results After intervention, the TP was superior to NTP for the sit-and-reach test, with a large effect size (d = 0.87; p = 0.035), with no differences between groups for the other tests. Intragroup comparisons showed significant differences ( p &lt; 0.05) for TP and NTP for improvement in 10-RM knee extensors and vertical jump measurements, while only TP showed significant intragroup improvement ( p &lt; 0.05) for the sit-and-reach test. A greater chance of experiencing pain or other discomfort as a result of exercise was shown by NTP (OR = 4.20, CI 95% 0.69 to 25.26). Conclusion Our findings demonstrated that stretching exercises performed at the beginning of sessions in a Pilates program did not impair or enhance the development of strength, vertical jump height and muscular endurance in young women. However, only the Pilates program with stretching improved flexibility and reduced the chances of adverse events such as musculoskeletal pain and other discomfort resulting from the exercise protocol. ClinicalTrials.gov NCT05538520, prospectively registered on September 16, 2022.

STRETCHING AND FLEXIBILITY: A RANGE OF MOTION FOR GAMES AND SPORTS

Type of study: systematic review

Number of citations: 25

Year: 2020

Authors: Md. Hamidur Rahman, Muhammad Shahidul Islam

Journal: European Journal of Physical Education and Sport Science

Journal ranking: brak

Key takeaways: Regular flexibility training improves muscle strength, balance, and core stability, ensuring optimal performance in games and sports.

Abstract: Flexibility is understood as the range of motion of a joint. Specifically, structured stretching exercises are used to improve flexibility. Exercising stretching is commonly practiced before any athletic activity takes place. To avoid sport injury, the range of motion is maintained, and muscle strength requires regular flexibility training. The present study, on the whole, reviews the respective literature sources. For this reason, the purpose of this study is to uphold the types and nature of stretching that produces the flexibility required for the performance of games and sports. Researchers collected scientific evidence through online databases: PubMed, Google Scholar, Google Advance Search and also searched sensibly via offline sources: recognized journals, articles, books, theses, and related literatures. After analyzing the stretching and flexibility in detail the authors suggested some specific stretchings that centered not just on flexibility but also on strength, balance and core stability. Through the discussion, the muscle is reported to be stretched properly, the underlying joints are made more flexible, and the range of motion is increased. Article visualizations:

Effects of Stretching on Injury Risk Reduction and Balance

Type of study: literature review

Number of citations: 33

Year: 2021

Authors: David G. Behm, A. Kay, G. S. Trajano, S. Alizadeh, A. Blazevich

Journal: Journal of Clinical Exercise Physiology

Journal ranking: brak

Key takeaways: Stretching can reduce injury incidence and improve balance, but optimal training plans for both acute and chronic stretching remain unclear.

Abstract: Evidence for the effectiveness of acute and chronic stretching for improving range of motion is extensive. Improved flexibility can positively impact performances in activities of daily living and both physical and mental health. However, less is known about the effects of stretching on other aspects of health such as injury incidence and balance. The objective of this review is to examine the existing literature in these areas. The review highlights that both pre-exercise and chronic stretching can reduce musculotendinous injury incidence, particularly in running-based sports, which may be related to the increased force available at longer muscle lengths (altered force-length relationship) or reduced active musculotendinous stiffness, among other factors. Evidence regarding the acute effects of stretching on balance is equivocal. Longer-term stretch training can improve balance, which may contribute to a decreased incidence of falls and associated injuries and may thus be recommended as an important exercise modality in those with balance deficits. Hence, both acute and chronic stretching seem to have positive effects on injury incidence and balance, but optimum training plans are yet to be defined.

A device-based stretch training for office workers resulted in increased range of motion especially at limited baseline flexibility

Type of study: non-rct experimental

Number of citations: 2

Year: 2020

Authors: L. Fräulin, Fabian Holzgreve, J. Hänel, Natalie Filmann, Helmut Schmidt, Andreas Bader, M. Frei, D. Groneberg, A. V. Mark, Daniela Ohlendorf

Journal: Work

Journal ranking: brak

Key takeaways: The 'five-Business' stretch training effectively increases range of motion in office workers, especially when baseline flexibility is limited.

Abstract: BACKGROUND: It is unclear whether and under which conditions stretch training programs lead to gains in flexibility when applied in work health promotion for office workers in order to reduce musculoskeletal disorders (MSD). OBJECTIVE: The aim of this study was to analyze whether the stretch training “five-Business” leads to gains in range of motion (ROM). Furthermore, the influence of baseline flexibility and socio-demographic factors (sex, age, weight, height and body mass index (BMI)) on trainability was assessed. METHODS: 161 office workers (n = 45 female; n = 116 male) without major MSD were recruited. Over three months, a standardized static stretch training (“five-Business”) was executed on a device, supervised twice per week for 10 min. ROM was assessed using a digital inclinometer (shoulder, hip and trunk extension) and a tape measure (fingertip-to-floor and lateral inclination). RESULTS: ROM gains (p≤0.001) were present in all tests, except for the hip extension. ROM changes correlated moderately (0.24–0.62) with the baseline flexibility (p≤0.001). Subjects with limited flexibility reached the largest gains (1.41–25.33%). Regarding the socio-demographic factors only one low correlation occurred (weight - retroflexion; –0.177). CONCLUSION: The “five-Business” stretch training effectively increases ROM in office workers, especially when baseline flexibility is limited.

The Case for Retiring Flexibility as a Major Component of Physical Fitness

Type of study:

Number of citations: 87

Year: 2019

Authors: James L. Nuzzo

Journal: Sports Medicine

Journal ranking: Q1

Key takeaways: Retiring flexibility as a major component of physical fitness simplifies fitness batteries, saves time and resources, and allows for more robust health benefits from other exercise modalities, such as resistance training.

Abstract: Flexibility refers to the intrinsic properties of body tissues that determine maximal joint range of motion without causing injury. For many years, flexibility has been classified by the American College of Sports Medicine as a major component of physical fitness. The notion flexibility is important for fitness has also led to the idea static stretching should be prescribed to improve flexibility. The current paper proposes flexibility be retired as a major component of physical fitness, and consequently, stretching be de-emphasized as a standard component of exercise prescriptions for most populations. First, I show flexibility has little predictive or concurrent validity with health and performance outcomes (e.g., mortality, falls, occupational performance) in apparently healthy individuals, particularly when viewed in light of the other major components of fitness (i.e., body composition, cardiovascular endurance, muscle endurance, muscle strength). Second, I explain that if flexibility requires improvement, this does not necessitate a prescription of stretching in most populations. Flexibility can be maintained or improved by exercise modalities that cause more robust health benefits than stretching (e.g., resistance training). Retirement of flexibility as a major component of physical fitness will simplify fitness batteries; save time and resources dedicated to flexibility instruction, measurement, and evaluation; and prevent erroneous conclusions about fitness status when interpreting flexibility scores. De-emphasis of stretching in exercise prescriptions will ensure stretching does not negatively impact other exercise and does not take away from time that could be allocated to training activities that have more robust health and performance benefits.

Improvements in Flexibility Depend on Stretching Duration.

Type of study: rct

Number of citations: 7

Year: 2023

Authors: Konstantin Warneke, K. Wirth, Michael Keiner, S. Schiemann

Journal: International journal of exercise science

Journal ranking: Q2

Key takeaways: Stretching for 60 minutes per day significantly improves flexibility in the plantar flexors, with the highest increase in range of motion measured via the goniometer of the orthosis.

Abstract: To improve flexibility, stretching is most commonly used and in training interventions duration-dependent effects are hypothesized. However, there are strong limitations in used stretching protocols in most studies, particularly regarding documentation of intensity and performed procedure. Thus, aim of this study was to compare different stretching durations on flexibility in the plantar flexors and to exclude potential biases. Eighty subjects were divided into four groups performing daily stretching training of 10min (IG10), 30min (IG30) and 1h (IG60) and one control group (CG). Flexibility was measured in bended and extended knee joint. Stretching was performed with a calf muscle stretching orthosis to ensure long-lasting stretching training. Data were analysed with a two-way ANOVA for repeated measures on two variables. Two-way ANOVA showed significant effects for time (η2 = 0.557-0.72, p < 0.001) and significant interaction effects for time × group (η2 = 0.39-0.47, p < 0.001). Flexibility in the knee to wall stretch improved with 9.89-14.46% d = 0.97-1.49 and 6.07-16.39% with d = 0.38-1.27 when measured via the goniometer of the orthosis. All stretching times led to significant increases in flexibility in both tests. While there were no significant differences measured via the knee to wall stretch between the groups, the range of motion measurement via the goniometer of the orthosis showed significantly higher improvements in flexibility depending on stretching duration with the highest increase in both tests with 60 minutes of stretch per day.

The Effect of Stretching Exercises Applied to Caregivers of Children with Development Disabilities on Musculoskeletal Muscle Mobility and Respiratory Function

Type of study: rct

Number of citations: 0

Year: 2024

Authors: Amine Ataç, Ebrar Atak

Journal: International Journal of Environmental Research and Public Health

Journal ranking: Q2

Key takeaways: Stretching exercises applied to the hamstrings significantly improved musculoskeletal flexibility, chest mobility, and respiratory function in healthcare professionals caring for children with developmental delays.

Abstract: We aimed to investigate the effect of stretching exercises applied to the hamstring, one of the posterior muscle chains, on musculoskeletal flexibility, chest mobility, and respiratory function. Proprioceptive neuromuscular facilitation and static stretching exercises were applied to 30 healthcare personnel caring for children with developmental delays using a crossover randomized study design. Posterior muscle chain mobility was assessed using the popliteal angle test (PAT) for the hamstring muscle, the mobility of the lumbar muscles was assessed using the Schober test (ST), and the mobility of the posterior chain muscles as a whole was assessed using the finger-to-floor distance test. Chest mobility was measured using chest circumference measurements and lung volumes were measured using the pulmonary function test (PFT). The results showed that stretching exercises applied to the hamstrings led to significant improvements in PAT, ST, and chest mobility in the direction of maximal expiration (p < 0.05), without being superior to each other. Ten males (33.3%) and twenty females (66.7%) who met the inclusion criteria were analyzed. The mean age of the participants was 26.6 ± 5.9 years, the mean height was 169.53 ± 8.67 cm, the mean weight was 65.26 ± 12.03 kg, and the mean body mass index was 22.58 ± 3 kg/m2. Chest inspiratory mechanics also showed a low positive correlation with posterior muscle mobility (r = 0.381; p = 0.038). There was no significant change in PAT. Within the framework of the myofascial theory, stretching exercises that can contribute positively to the musculoskeletal and respiratory system structures of healthcare professionals can be recommended and encouraged to healthcare professionals.

The Influence of Resistance Training on Joint Flexibility in Healthy Adults: A Systematic Review, Meta-analysis, and Meta-regression

Type of study: meta-analysis

Number of citations: 1

Year: 2024

Authors: Francesco Favro, Enrico Roma, S. Gobbo, V. Bullo, A. di Blasio, L. Cugusi, M. Bergamin

Journal: Journal of Strength and Conditioning Research

Journal ranking: Q1

Key takeaways: Resistance training can improve joint flexibility in healthy adults, with high-intensity protocols having a magnified effect, but the high overall risk of bias and substantial heterogeneity limit definitive conclusions.

Abstract: Supplemental Digital Content is Available in the Text. Abstract Favro, F, Roma, E, Gobbo, S, Bullo, V, Di Blasio, A, Cugusi, L, and Bergamin, M. The influence of resistance training on joint flexibility in healthy adults: A systematic review, meta-analysis, and meta-regression. J Strength Cond Res 39(3): 386–397, 2025—Joint flexibility is a key component of physical fitness. Despite the large body of evidence regarding the effectiveness of muscle stretching exercises, little is known about the effect of resistance training on flexibility. A systematic search was conducted on 9 academic search instruments; inclusion criteria were as follows: healthy adult participants (age ≥18 years); resistance training intervention (duration ≥4 weeks); at least one flexibility outcome. Risk of bias was assessed using the RoB-2 and ROBINS-I tools. A 3-level meta-analysis was conducted, with multiple outcomes nested within each study. A moderator analysis was conducted by fitting a meta-regression model. Significance level was set at p < 0.05. We included 36 studies (1,469 participants). None of the included papers resulted at a low risk of bias. The pooled effect size for resistance training on flexibility was g = 0.6325, with 95% CI: 0.4762 to 0.7888 (p < 0.0001). There was a substantial amount of heterogeneity between studies. Exercise intensity was a significant moderator (p < 0.0225, high vs low), based on 129 and unique effect sizes, and sex (p = 0.0429). Activity level and age were nonsignificant moderators. Resistance training could be implemented as a strategy to improve joint flexibility, with high-intensity protocols resulting in a magnified effect. However, the high overall risk of bias and substantial heterogeneity limit our ability to draw definitive conclusions.

Resistance Training Induces Improvements in Range of Motion: A Systematic Review and Meta-Analysis

Type of study: meta-analysis

Number of citations: 49

Year: 2023

Authors: S. Alizadeh, A. Daneshjoo, A. Zahiri, Saman Hadjizedah Anvar, R. Goudini, Jared Hicks, A. Konrad, David G. Behm

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

Journal ranking: Q1

Key takeaways: Resistance training can improve range of motion, and stretching prior to or after resistance training may not be necessary to enhance flexibility.

Abstract: Abstract Background Although it is known that resistance training can be as effective as stretch training to increase joint range of motion, to date no comprehensive meta-analysis has investigated the effects of resistance training on range of motion with all its potential affecting variables. Objective The objective of this systematic review with meta-analysis was to evaluate the effect of chronic resistance training on range of motion compared either to a control condition or stretch training or to a combination of resistance training and stretch training to stretch training, while assessing moderating variables. Design For the main analysis, a random-effect meta-analysis was used and for the subgroup analysis a mixed-effect model was implemented. Whilst subgroup analyses included sex and participants’ activity levels, meta-regression included age, frequency, and duration of resistance training. Data Sources Following the systematic search in four databases (PubMed, Scopus, SPORTDiscus, and Web of Science) and reference lists, 55 studies were found to be eligible. Eligibility Criteria Controlled or randomized controlled trials that separately compared the training effects of resistance training exercises with either a control group, stretching group, or combined stretch and resistance training group on range of motion in healthy participants. Results Resistance training increased range of motion (effect size [ES] = 0.73; p &lt; 0.001) with the exception of no significant range of motion improvement with resistance training using only body mass. There were no significant differences between resistance training versus stretch training (ES = 0.08; p = 0.79) or between resistance training and stretch training versus stretch training alone (ES = − 0.001; p = 0.99). Although “trained or active people” increased range of motion (ES = 0.43; p &lt; 0.001) “untrained and sedentary” individuals had significantly ( p = 0.005) higher magnitude range of motion changes (ES = 1.042; p &lt; 0.001). There were no detected differences between sex and contraction type. Meta-regression showed no effect of age, training duration, or frequency. Conclusions As resistance training with external loads can improve range of motion, stretching prior to or after resistance training may not be necessary to enhance flexibility.

Functional state of team sports athletes in the annual training cycle

Type of study:

Number of citations: 4

Year: 2024

Authors: Dmitrii Babaskin, Farhod Masharipov, Olga Savinkova, Natalia Shustikova, Nina Volkova

Journal: Retos

Journal ranking: Q2

Key takeaways: Team sports athletes show low flexibility and joint mobility at the end of the competition period, suggesting overstrain, but positive changes in the musculoskeletal system during the preparatory period can partially restore it.

Abstract: Determination of the dynamics of the functional state of the musculoskeletal system of team sports athletes in the annual training cycle. The achievement of this goal will allow for providing scientifically-based management of training and competitive processes in the annual training cycle and contribute to the normalization of the functional state of the athlete's musculoskeletal system. The authors assessed the functional state of the musculoskeletal system of athletes involved in football, handball, and field hockey, using goniometry, and stabilometry, as well as testing physical abilities, associated with the flexibility of the joints (forward bend from a standing position (on the bench), bridge, transverse and longitudinal (best of 2 possible), splits). Testing was conducted during the annual training cycle, after the competitive period, and at the beginning and at the end of the preparatory period. Assessment of the functional state of the musculoskeletal system of athletes at the end of the competition period showed the low and below average flexibility levels. Static support ability (stabilometry) and joint mobility (goniometry) were below average and average levels. Decrease in static support ability testified to violations of the vestibular apparatus and proprioceptive sensitivity, which have a significant impact on balance. The low results of joint flexibility and mobility indicated the lack of elasticity of the musculoskeletal apparatus, which indicated the presence of overstrain. Diagnosed positive changes in the state of the musculoskeletal system of athletes at the beginning and at the end of the preparatory period, regardless of the team sport, indicated a partial restoration of the functional state of the musculoskeletal system during the transition period. According to the results of the study, recommendations were given for including in the training process, along with prestretching, corrective and preventive exercises based on the use of the myofascial relaxation technique, which contribute to the restoration of the functional state of the musculoskeletal system of team sports athletes. Keywords: football players, handball players, hockey players, functional state, musculoskeletal system, flexibility, stabilometry, goniometry.

Fourteen weeks of multicomponent training associated with flexibility training modifies postural alignment, joint range of motion and modulates blood pressure in physically inactive older women: a randomized clinical trial

Type of study: rct

Number of citations: 6

Year: 2023

Authors: A. C. S. Sobrinho, C. J. R. Benjamim, Mariana Luciano de Almeida, G. Rodrigues, Laryssa Grazielle Feitosa Lopes, J. G. Ribeiro de Lima, C. B. Bueno Júnior

Journal: Frontiers in Physiology

Journal ranking: Q2

Key takeaways: Multicomponent training combined with flexibility training improves blood pressure, postural alignment, and joint range of motion in physically inactive older women.

Abstract: Background: Body relaxation and pain reduction are some of the reported benefits of flexibility training (through active stretching exercises), however their effects on posture and blood circulation are uncertain. We aimed to investigate the effects of flexibility training (through active stretching exercises) in combination with multicomponent training (MT) on blood pressure (BP), and the correlation with changes in body alignment and flexibility in physically inactive women. Methods: Women aged 60–70 years were into three groups: multicomponent training group (MT), multicomponent training plus flexibility training group (FT), and control group (CG). After randomization, the resting blood pressure was measured and the participants were reallocated into subgroups according to pressure values >130/80 mmHg (This classification is according to the American Heart Association (AHA), resulting in the subgroups: flexibility training (FT); flexibility training for hypertensive patients (FTSAH); multicomponent training (MT); multicomponent training for hypertensive patients (MTSAH); control group (CG); control group of hypertensive patients (CGSAH). The interventions lasted 14 weeks. Systolic (sBP) and diastolic (dBP) BP, range of motion (flexion and extension), and postural analysis by asymmetry in the frontal plane and asymmetry in the sagittal plane, displacement and the flexibility test were collected before (Pre) and after training (Post). In total, 141 women participated in the study (without SAH: FT = 23, MT = 20, and CG = 21; with SAH: FTSAH = 28, MTSAH = 23, and CGSAH = 26). Results: Systolic blood pressure, in the pre and post moments were: FT (116 ± 6.7 vs. 114 ± 4.7); FTSAH (144 ± 16.5 vs. 121 ± 10.1); MT: (120 ± 6.8 vs. 121 ± 7.3); MTSAH: (137 ± 10.6 vs. 126 ± 13.0); CG: (122 ± 5.3 vs. 133 ± 19.2); and CGSAH: (140 ± 9.7 vs. 143 ± 26.2), presenting an F value (p-value - group x time) of 12.00 (<0.001), with improvement in the groups who trained. The diastolic blood pressure in the pre and post moments were: FT (71 ± 4.7 vs. 74 ± 6.8); FTSAH (88 ± 9.6 vs. 70 ± 12.0); MT: (74 ± 4.5 vs. 77 ± 11.7); MTSAH: (76 ± 10.4 vs. 76 ± 10.2); CG: (69 ± 7.11 vs. 82 ± 11.4); and CGSAH: (76 ± 13.4 vs. 86.6 ± 7.7), presenting an F value (p-value - group x time) of 8.00 (p < 0.001), with improvement in the groups who trained. In the Elastic Net Regression, sBP was influenced by height (β: −0.044); hip flexion (β: 0.071); Shoulder extension (β: 0.104); low back flexion (β: 0.119) and dBP (β: 0.115). In the Elastic Net Regression, dBP was influenced by asymmetry in the sagittal plane variables (0.040); asymmetry in the frontal plane (β: 0.007); knee flexion (β: −0.398); BM (β: 0.007); Shoulder flexion (β: −0.142); Hip flexion (β: −0.004); sBP (β: 0.155) and Ankle Flexion (β: −0.001). Conclusion: The displacement of the asymmetry in the frontal plane and asymmetry in the sagittal plane, and the increase in the flexion position in the hip, lumbar, head, and knee regions, influenced the highest-pressure levels. Multicomponent training associated with flexibility training promoted improvement in body alignment, COM, and joint angles, and decreased blood pressure.

STUDY OF THE DEVELOPMENT OF FLEXIBILITY AMONG STUDENTS OF SENIOR SCHOOL AGE

Type of study:

Number of citations: 0

Year: 2023

Authors: V. Tyshchenko, O. Ivanska, K. Shekhovtsova, D. Kobezska

Journal: Physical education and Sports

Journal ranking: brak

Key takeaways: Physical training in comprehensive schools effectively increases flexibility indicators in both boys and girls, with more emphasis on spine joint flexibility in the experimental group.

Abstract: Flexibility is necessary to maintain proper posture, is an important component of fitness and health, and can protect against musculoskeletal injuries, while a lack of proper flexibility can cause disease and dysfunction of the musculoskeletal system. Well-developed flexibility ensures fast, economical and technically correct human movement. Traditionally such indicators as ballistic stretching, proprioceptive neuromuscular facilitation and static stretching are defined. The purpose of the research – assessment of the effectiveness of physical training in comprehensive school, in order to develop flexibility of senior school age students. The object of the research is the educational process in physical training in comprehensive school. The subject of the research is the dynamics of indicators of flexibility of senior school age students in comprehensive school under the influence of physical training. Research methods: theoretical analysis of scientific-methodical literature, pedagogical observation, pedagogical experiment, testing of flexibility indicators, methods of mathematical statistics. Research results. The research has revealed that the means used in physical education classes in the control group, aimed at development of flexibility, allow to maintain the development of flexibility indicators at the previous level. The means that have been used in the experimental group have made it possible to increase the flexibility indicators of boys and girls based on the results of all tests. Although probable changes are observed according to the results of the test “tilt of the body forward from the sitting position” among boys and girls of the 10th and 11th forms, and according to the results of the “cross twine” test of the girls of the 10th grade. The results of the research can be used by physical culture teachers in the educational process of physical education aimed at developing the flexibility of senior school age students. Conclusions. Analyzing the results of the research, it should be noted that the likely improvement of flexibility indicators among the girls of the 10th and 11th grades of the experimental group at the end of the research compared with the beginning according to the results of the test “tilt of the body forward from the sitting position” may be explained by the fact that the test “tilt of the body forward from the sitting position” is normative in the school physical education program, and in physical education classes more attention is paid to the development of the flexibility of the spine joints.

Biomechanical, Healing and Therapeutic Effects of Stretching: A Comprehensive Review

Type of study: literature review

Number of citations: 10

Year: 2023

Authors: E. Zvetkova, E. Koytchev, I. Ivanov, S. Ranchev, A. Antonov

Journal: Applied Sciences

Journal ranking: Q2

Key takeaways: Static stretching (SS) improves flexibility, reduces muscle stiffness, and aids in joint injury prevention and treatment, with potential benefits for both healthy and ill individuals.

Abstract: Characterized in biomedical terms, stretching exercises have been defined as movements applied by external and/or internal forces to increase muscle and joint flexibility, decrease muscle stiffness, elevate the joint range of motion (ROM), increase the length of the “muscle–tendon” morpho-functional unit, and improve joint, muscle, and tendon movements, contraction, and relaxation. The present review examines and summarizes the initial and recent literature data related to the biomechanical, physiological, and therapeutic effects of static stretching (SS) on flexibility and other physiological characteristics of the main structure and the “joint–ligament–tendon–muscle” functional unit. The healing and therapeutic effects of SS, combined with other rehabilitation techniques (massage, foam rolling with and without vibrations, hot/cold therapy, etc.), are discussed in relation to the creation of individual (patient-specific) or group programs for the treatment and prevention of joint injuries, as well as for the improvement of performance in sports. From a theoretical point of view, the role of SS in positively affecting the composition of the connective tissue matrix is pointed out: types I–III collagen syntheses, hyaluronic acid, and glycosaminoglycan (GAG) turnover under the influence of the transforming growth factor beta-1 (TGF-β-1). Different variables, such as collagen type, biochemistry, elongation, and elasticity, are used as molecular biomarkers. Recent studies have indicated that static progressive stretching therapy can prevent/reduce the development of arthrogenic contractures, joint capsule fibrosis, and muscle stiffness and requires new clinical applications. Combined stretching techniques have been proposed and applied in medicine and sports, depending on their long- and short-term effects on variables, such as the ROM, EMG activity, and muscle stiffness. The results obtained are of theoretical and practical interest for the development of new experimental, mathematical, and computational models and the creation of efficient therapeutic programs. The healing effects of SS on the main structural and functional unit—“joint–ligament–tendon–muscle”—need further investigation, which can clarify and evaluate the benefits of SS in prophylaxis and the treatment of joint injuries in healthy and ill individuals and in older adults, compared to young, active, and well-trained persons, as well as compared to professional athletes.

Effect of 12-Week Dynamic Stretching of Ankle Plantar Flexors on Joint Flexibility and Musculoskeletal Properties in The Contralateral Muscle.

Type of study:

Number of citations: 0

Year: 2025

Authors: Naoki Ikeda, Kazuya Hiratsuka, Tadao Isaka

Journal: Journal of sports science & medicine

Journal ranking: Q1

Key takeaways: A 12-week dynamic stretching program can reduce muscle stiffness and improve joint flexibility without affecting muscle strength, while also enhancing contralateral joint flexibility without altering muscle stiffness or strength.

Abstract: Dynamic stretching (DS) is a conditioning technique commonly used in sports. However, its effects on contralateral joint flexibility and elastic properties of the targeted muscle over several weeks remain unclear. Similarly, its impact on muscle functions, such as force or power exertion, is poorly understood. This study aimed to examine the effects of a 12-week DS program targeting the ankle plantar flexors on the joint flexibility, muscle strength, and elastic properties of the plantar flexors in stretched and contralateral legs. Eighteen healthy young adults (12 males and six females, aged 18-24 years) participated in this study. DS was performed on one leg of the ankle plantar flexors for 12 weeks (3 days weekly), while the other leg served as a non-intervention. Dorsiflexion range of motion (DFROM), muscle stiffness, and ankle plantar flexion strength (rate of torque development and isokinetic muscle strength) were assessed before and after the intervention. The muscle stiffness was measured using shear wave elastography on the gastrocnemius. DFROM significantly increased in both conditions (p < 0.05), whereas gastrocnemius stiffness significantly decreased only in the DS condition (p < 0.05). No significant changes were observed in the non-intervention condition. The ankle plantar flexion rates of torque development and isokinetic strength did not change in either condition. These findings suggest that 12 weeks of DS can reduce muscle stiffness and improve joint flexibility without affecting muscle strength while enhancing contralateral joint flexibility without altering muscle stiffness or strength.

Effects of a 12-Week Chronic Stretch Training Program at Different Intensities on Joint and Muscle Mechanical Responses: A Randomized Clinical Trial.

Type of study: rct

Number of citations: 16

Year: 2020

Authors: N. B. Beltrão, Camila Ximenes Santos, V. M. A. de Oliveira, A. L. Pirauá, David G. Behm, A. Pitangui, R. C. de Araújo

Journal: Journal of sport rehabilitation

Journal ranking: Q2

Key takeaways: Stretching with either low or high discomfort intensities effectively increases joint maximal range of motion, without affecting ROM, stiffness, fascicle angle and length, or affective response differences.

Abstract: CONTEXT Stretching intensity is an important variable that can be manipulated with flexibility training. However, there is a lack of evidence regarding this variable and its prescription in stretching programs. OBJECTIVE To investigate the effects of 12 weeks of knee flexor static stretching at different intensities on joint and muscle mechanical properties. DESIGN A randomized clinical trial. SETTING Laboratory. PARTICIPANTS A total of 14 untrained men were allocated into the low- or high-intensity group. MAIN OUTCOME MEASURES Assessments were performed before, at 6 week, and after intervention (12 wk) for biceps femoris long head architecture (resting fascicle length and angle), knee maximal range of motion (ROM) at the beginning and maximal discomfort angle, knee maximal tolerated passive torque, joint passive stiffness, viscoelastic stress relaxation, knee passive torque at a given angle, and affective responses to training. RESULTS No significant differences were observed between groups for any variable. ROM at the beginning and maximal discomfort angle increased at 6 and 12 weeks, respectively. ROM significantly increased with the initial angle of discomfort (P < .001, effect size = 1.38) over the pretest measures by 13.4% and 14.6% at the 6- and 12-week assessments, respectively, and significantly improved with the maximal discomfort angle (P < .001, effect size = 1.25) by 15.6% and 18.8% from the pretest to the 6- and 12-week assessments, respectively. No significant effects were seen for muscle architecture and affective responses. Initial viscoelastic relaxation for the low-intensity group was lower than ending viscoelastic relaxation. CONCLUSION These results suggest that stretching with either low or high discomfort intensities are effective in increasing joint maximal ROM, and that does not impact on ROM, stiffness, fascicle angle and length, or affective response differences.

Acute and Chronic Effects of Supervised Flexibility Training in Older Adults: A Comparison of Two Different Conditioning Programs

Type of study: rct

Number of citations: 14

Year: 2022

Authors: Stefano La Greca, Mariano Rapali, Giuliano Ciaprini, Luca Russo, M. G. Vinciguerra, R. Di Giminiani

Journal: International Journal of Environmental Research and Public Health

Journal ranking: Q2

Key takeaways: Both strength and static stretching exercises, as well as dynamic and static stretching exercises, effectively improve flexibility in older adults, reducing the risk of falls.

Abstract: Flexibility training is a fundamental biological process that improves the quality of life of the elderly by improving the ranges of motion of joints, postural balance and locomotion, and thus reducing the risk of falling. Two different training programs were assessed acutely and after 12 weeks by means of the sit-and-reach test. Thirty-one healthy older adults were randomly divided into three groups: the Experiment I group (Exp) performed strength and static stretching exercises; the Experiment II group performed dynamic and static stretching exercises; and participants assigned to the control group maintained a sedentary lifestyle for the entire period of the study. Flexibility acutely increased in Exp I by the first (ΔT0 = 7.63 ± 1.26%; ES = 0.36; p = 0.002) and second testing sessions (ΔT1 = 3.74 ± 0.91%; ES = 0.20; p = 0.002). Similarly, it increased in Exp II significantly by the first (ΔT0 = 14.21 ± 3.42%; ES = 0.20; p = 0.011) and second testing sessions (ΔT1 = 9.63 ± 4.29%; ES = 0.13; p = 0.005). Flexibility significantly increased over the 12 weeks of training in Exp I (ΔT0 − T1 = 9.03 ± 3.14%; ES = 0.41; p = 0.020) and Exp II (ΔT0 − T1 = 22.96 ± 9.87%; ES = 0.35; p = 0.005). The acute and chronic differences between the two groups were not significant (p > 0.05). These results suggest the effectiveness of different exercise typologies in improving the flexibility of the posterior muscular chains in older adults. Therefore, the selection of a program to optimize training interventions could be based on the physical characteristics of the participants.

Acute Effects of Various Stretching Techniques on Range of Motion: A Systematic Review with Meta-Analysis

Type of study: meta-analysis

Number of citations: 33

Year: 2023

Authors: D. Behm, S. Alizadeh, A. Daneshjoo, Saman Hadjizedah Anvar, Andrew Graham, Ali Zahiri, R. Goudini, Chris Edwards, Robyn Culleton, Carina Scharf, A. Konrad

Journal: Sports Medicine - Open

Journal ranking: Q1

Key takeaways: A single bout of stretching can provide small improvements in range of motion for most muscles, unaffected by stretch intensity, trained state, stretching techniques, or sex.

Abstract: Although stretching can acutely increase joint range of motion (ROM), there are a variety of factors which could influence the extent of stretch-induced flexibility such as participant characteristics, stretching intensities, durations, type (technique), and muscle or joint tested. The objective of this systematic review and meta-analysis was to investigate the acute effects of stretching on ROM including moderating variables such as muscles tested, stretch techniques, intensity, sex, and trained state. A random-effect meta-analysis was performed from 47 eligible studies (110 effect sizes). A mixed-effect meta-analysis subgroup analysis was also performed on the moderating variables. A meta-regression was also performed between age and stretch duration. GRADE analysis was used to assess the quality of evidence obtained from this meta-analysis. The meta-analysis revealed a small ROM standard mean difference in favor of an acute bout of stretching compared to non-active control condition (ES = −0.555; Z = −8.939; CI (95%) −0.677 to −0.434; p < 0.001; I2 = 33.32). While there were ROM increases with sit and reach (P = 0.038), hamstrings (P < 0.001), and triceps surae (P = 0.002) tests, there was no change with the hip adductor test (P = 0.403). Further subgroup analyses revealed no significant difference in stretch intensity (P = 0.76), trained state (P = 0.99), stretching techniques (P = 0.72), and sex (P = 0.89). Finally, meta-regression showed no relationship between the ROM standard mean differences to age (R2 = −0.03; P = 0.56) and stretch duration (R2 = 0.00; P = 0.39), respectively. GRADE analysis indicated that we can be moderately confident in the effect estimates. A single bout of stretching can be considered effective for providing acute small magnitude ROM improvements for most ROM tests, which are not significantly affected by stretch intensity, participants' trained state, stretching techniques, and sex.

Acute effect of static stretching on non-muscular tissue stiffness and joint flexibility: a comparative study between older and young men

Type of study: non-rct experimental

Number of citations: 4

Year: 2023

Authors: Kosuke Hirata, R. Akagi

Journal: European Journal of Applied Physiology

Journal ranking: Q1

Key takeaways: Static stretching reduces sciatic nerve stiffness and improves joint flexibility in older men, but not in young men.

Abstract: PurposeNon-muscular tissue stiffness is assumed to have a negative impact on joint flexibility, and a reduction in non-muscular tissue stiffness may be important, especially in older adults. The present study aimed to compare the acute effects of static stretching on non-muscular tissue stiffness between older and young adults and to investigate whether a decrease in tissue stiffness improves joint flexibility.MethodsTwenty older (62–83 years) and 20 young (21–24 years) males participated. Ankle dorsiflexion static stretching (five sets of 90 s each) was performed, and before and after stretching, the ankle dorsiflexion range of motion (RoM), passive ankle joint stiffness, and shear wave speed (SWS) (an index of stiffness) of the sciatic nerve, tibial nerve, and posterior thigh fascia were measured.ResultsStretching led to an increase in RoM and a decrease in passive joint stiffness in both groups (P < 0.001) with no significant between-group differences (P ≥ 0.055). The between-group difference in the effect of stretching on SWS was evident only for the sciatic nerve, and a decline in sciatic nerve SWS was only observed in the older adult group (pre-stretching: 2.5 ± 0.3 m/s; post-stretching: 2.3 ± 0.4 m/s; P = 0.027). A significant positive repeated-measures correlation was observed between the sciatic nerve SWS and passive joint stiffness (P = 0.014, r_rm = 0.540).ConclusionThe reduction in sciatic nerve stiffness by stretching was noticeable in older men and led to improved joint flexibility. These findings may provide insight into tissue adaptation by stretching and may be used to explore effective exercises for improving joint flexibility in older adults.

Comparing the effects of self-myofascial release with static stretching on ankle range-of-motion in adolescent athletes.

Type of study: rct

Number of citations: 160

Year: 2015

Authors: Jakob Škarabot, Chris Beardsley, Igor Štirn

Journal: International journal of sports physical therapy

Journal ranking: Q2

Key takeaways: Foam rolling and static stretching both increase ankle flexibility, but FR+SS has a more additive effect on increasing flexibility in resistance-trained adolescents.

Abstract: BACKGROUND Increased flexibility is often desirable immediately prior to sports performance. Static stretching (SS) has historically been the main method for increasing joint range-of-motion (ROM) acutely. However, SS is associated with acute reductions in performance. Foam rolling (FR) is a form of self-myofascial release (SMR) that also increases joint ROM acutely but does not seem to reduce force production. However, FR has never previously been studied in resistance-trained athletes, in adolescents, or in individuals accustomed to SMR. OBJECTIVE To compare the effects of SS and FR and a combination of both (FR+SS) of the plantarflexors on passive ankle dorsiflexion ROM in resistance-trained, adolescent athletes with at least six months of FR experience. METHODS Eleven resistance-trained, adolescent athletes with at least six months of both resistance-training and FR experience were tested on three separate occasions in a randomized cross-over design. The subjects were assessed for passive ankle dorsiflexion ROM after a period of passive rest pre-intervention, immediately post-intervention and after 10, 15, and 20 minutes of passive rest. Following the pre-intervention test, the subjects randomly performed either SS, FR or FR+SS. SS and FR each comprised 3 sets of 30 seconds of the intervention with 10 seconds of inter-set rest. FR+SS comprised the protocol from the FR condition followed by the protocol from the SS condition in sequence. RESULTS A significant effect of time was found for SS, FR and FR+SS. Post hoc testing revealed increases in ROM between baseline and post-intervention by 6.2% for SS (p < 0.05) and 9.1% for FR+SS (p < 0.05) but not for FR alone. Post hoc testing did not reveal any other significant differences between baseline and any other time point for any condition. A significant effect of condition was observed immediately post-intervention. Post hoc testing revealed that FR+SS was superior to FR (p < 0.05) for increasing ROM. CONCLUSIONS FR, SS and FR+SS all lead to acute increases in flexibility and FR+SS appears to have an additive effect in comparison with FR alone. All three interventions (FR, SS and FR+SS) have time courses that lasted less than 10 minutes. LEVEL OF EVIDENCE 2c.

Keeping Your Joints Flexible Throughout Life

Type of study:

Number of citations: 0

Year: 2023

Authors: A. Konrad, D. Behm

Journal: Frontiers for Young Minds

Journal ranking: brak

Key takeaways: Maintaining flexibility in joints is crucial for maintaining good health, especially in a sedentary lifestyle.

Abstract: People are built to move. To survive, not so long ago, we had to search for food every day as hunters or gatherers. In modern times, however, our way of life has changed drastically. We can buy our food at the supermarket and many people can do their work at a desk. As a result, we move less and sit for several hours every day. This is called a sedentary lifestyle. Sedentary activities can lead to a dramatic decrease in flexibility in the joints. To overcome those challenges, we can do a variety of activities such as performing sports that require the full range of motion of our joints, as well as doing stretch training, foam rolling, or resistance training.

Studing the influence of stretching on the effectiveness of «full body» strength training and on the recovery process in middle-aged women

Type of study:

Number of citations: 0

Year: 2024

Authors: O. Samoliuc, Tatiana Cheban

Journal: This bulletin of the Kamianets-Podilskyi National Ivan Ohiienko University. Physical education, Sport and Human Health

Journal ranking: brak

Key takeaways: Regular 40-minute stretching sessions on rest days between strength training improve strength, flexibility, and movement speed in middle-aged women, while also promoting recovery and reducing muscle pain.

Abstract: In this research, the effect of stretching on the effectiveness of full body strength training and on the recovery process after it in women aged 45-50 years was studied. It was assumed that the use of stretching exercises on a rest day between major strength loads can have a noticeable effect on physical fitness indicators (ability to perform control tests for speed, strength, flexibility) and on the degree of recovery (sensory perception in the form of a desire to exercise and the degree of muscle pain) in middle-aged women engaged in fitness. The purpose of the study is to improve the methods of recreational physical exercises of a power orientation with middle–aged women. Research objectives: analysis of current research in the field of methods of strength training and flexibility training with middle-aged women; development of a stretching training program for women 45-50 years old; assessment of the impact of additional stretching classes on strength, speed, flexibility and sensory perception after strength training in women 45-50 years old. Conclusions: Regular 40-minute stretching sessions containing dynamic active exercises and used on rest days between strength training according to the 'full body' program by women 45-50 years old for 8 months have a positive effect on strength, flexibility, and speed of movement. Also, this approach to alternating strength training and stretching can be effective for recovery after intense strength training. In the experimental group, significant positive changes were recorded in the following tests: squatting with a barbell (p <0.01), pulling up on a crossbar (p <0.01), leaning forward (p <0.01), chest press (p <0.05), understanding straight legs in the temple (p <0.05), muscular pain and limited movement (p <0.01), the desire to perform strength exercises (p <0.01).

Acute Effects of the Different Intensity of Static Stretching on Flexibility and Isometric Muscle Force

Type of study: non-rct experimental

Number of citations: 73

Year: 2017

Authors: S. Kataura, Shigeyuki Suzuki, Shingo Matsuo, Genki Hatano, M. Iwata, Kazuaki Yokoi, Wakako Tsuchida, Yasuhiro Banno, Y. Asai

Journal: Journal of Strength and Conditioning Research

Journal ranking: Q1

Key takeaways: Static stretching at greater intensity increases range of motion and decreases passive muscle-tendon stiffness, improving lower limb function and flexibility.

Abstract: Abstract Kataura, S, Suzuki, S, Matsuo, S, Hatano, G, Iwata, M, Yokoi, K, Tsuchida, W, Banno, Y, and Asai, Y. Acute effects of the different intensity of static stretching on flexibility and isometric muscle force. J Strength Cond Res 31(12): 3403–3410, 2017—In various fields, static stretching is commonly performed to improve flexibility, whereas the acute effects of different stretch intensities are unclear. Therefore, we investigated the acute effects of different stretch intensities on flexibility and muscle force. Eighteen healthy participants (9 men and 9 women) performed 180-second static stretches of the right hamstrings at 80, 100, and 120% of maximum tolerable intensity without stretching pain, in random order. The following outcomes were assessed as markers of lower limb function and flexibility: static passive torque (SPT), range of motion (ROM), passive joint (muscle-tendon) stiffness, passive torque (PT) at onset of pain, and isometric muscle force. Static passive torque was significantly decreased after all stretching intensities (p ⩽ 0.05). Compared with before stretching at 100 and 120% intensities, ROM and PT were significantly increased after stretching (p ⩽ 0.05), and passive stiffness (p = 0.05) and isometric muscle force (p ⩽ 0.05) were significantly decreased. In addition, ROM was significantly greater after stretching at 100 and 120% than at 80%, and passive stiffness was significantly lower after 120% than after 80% (p ⩽ 0.05). However, all measurements except SPT were unchanged after 80% intensity. There was a weak positive correlation between the intensities of stretching and the relative change for SPT (p ⩽ 0.05), a moderate positive correlation with ROM (p ⩽ 0.05), and a moderate positive correlation with passive stiffness (p ⩽ 0.05). These results indicate that static stretching at greater intensity is more effective for increasing ROM and decreasing passive muscle-tendon stiffness.

Effects of dynamic stretching of different duration on lower limb flexibility in male sport dancers: A randomized controlled trial

Type of study: rct

Number of citations: 0

Year: 2025

Authors: Jingzhen Wang, Fang Hu, Xuan Qiu, Han Li

Journal: Molecular &amp; Cellular Biomechanics

Journal ranking: brak

Key takeaways: Dynamic stretching improves lower limb flexibility in male sport dancers, with 20-minute warm-ups and 30-minute training sessions being most effective, with a more pronounced effect on the dominant limb due to its inherent biomechanical and neuromuscular advantages.

Abstract: In the field of sports training and teaching, stretching is regarded as a highly valuable technique, particularly in its capacity to facilitate gradual acclimatization of the body to the exercise state during the warm-up session and as a means of enhancing flexibility qualities. As the research on athletic training continues to deepen, the discussion on the respective advantages of static stretching and dynamic stretching is becoming increasingly prominent. In this study, dynamic stretching was selected as the primary intervention to investigate the effects of varying durations of dynamic stretching on the flexibility of the legs of male students majoring in sport dance, with a particular focus on the underlying biomechanical mechanisms. Method: The subjects were 40 male first- and second-year students majoring in physical education dance at Yichun College, randomly assigned to one of four groups of 10 students each. The methodology comprised a dynamic stretching warm-up and quality training prior to the commencement of regular sports dance teaching, after which the basic teaching session was initiated. The study employed SPSS 22.0 software to conduct a T-test to analyze the effects of different stretching durations on flexibility. SPSS 22.0 software was utilized to perform a T-test. Biomechanical parameters such as muscle fiber recruitment patterns, joint range of motion, and force generation during stretching were also measured and analyzed. Results: (1) Dynamic stretching in warm-ups and training can boost lower limb flexibility. Biomechanically, this is attributed to the activation of specific muscle groups and the modulation of connective tissue properties. A significant difference observed between dominant and non-dominant limbs, which may be related to differences in neuromuscular control and muscle fiber composition. (2) A 20-minute stretch in warm-ups and a 30-minute stretch in training were best for flexibility, showing a more pronounced effect on the dominant side. This could be due to the dominant limb's greater ability to generate force and adapt to biomechanical stress, as well as its more efficient neuromuscular coordination. (3) The right side, which corresponds to the dominant limb in most subjects, improved more than the left with dynamic stretching. This could be attributed to the greater neural activation and muscle recruitment efficiency, which are key biomechanical factors in the stretching response. (4) Although dynamic stretching is slower than static stretching in enhancing flexibility, consistent sessions exceeding 20 minutes can still yield positive results for both limbs though the dominant limb may benefit more initially., likely due to its pre-existing biomechanical advantages and more refined neuromuscular pathways. Conclusion: Dynamic stretching effectively improves lower limb flexibility, though more slowly than static stretching. Regular sessions over 20 min, especially 20-minute warm-ups and 30-minute training, can notably enhance flexibility, with a significant impact on the dominant limb, suggesting that while non-dominant limbs also benefit, the dominant limb may require less time to achieve similar flexibility improvements due to its inherent biomechanical and neuromuscular characteristics.

Resistance Training vs. Static Stretching: Effects on Flexibility and Strength

Type of study: rct

Number of citations: 108

Year: 2011

Authors: Sam K. Morton, J. Whitehead, R. Brinkert, D. Caine

Journal: Journal of Strength and Conditioning Research

Journal ranking: Q1

Key takeaways: Full-range resistance training can improve flexibility and strength as effectively as static stretching in untrained adults.

Abstract: Morton, SK, Whitehead, JR, Brinkert, RH, and Caine, DJ. Resistance training vs. static stretching: Effects on flexibility and strength. J Strength Cond Res 25(12): 3391–3398, 2011—The purpose of this study was to determine how full-range resistance training (RT) affected flexibility and strength compared to static stretching (SS) of the same muscle–joint complexes in untrained adults. Volunteers (n = 25) were randomized to an RT or SS training group. A group of inactive volunteers (n = 12) served as a convenience control group (CON). After pretesting hamstring extension, hip flexion and extension, shoulder extension flexibility, and peak torque of quadriceps and hamstring muscles, subjects completed 5-week SS or RT treatments in which the aim was to stretch or to strength train the same muscle–joint complexes over similar movements and ranges. Posttests of flexibility and strength were then conducted. There was no difference in hamstring flexibility, hip flexion, and hip extension improvement between RT and SS, but both were superior to CON values. There were no differences between groups on shoulder extension flexibility. The RT group was superior to the CON in knee extension peak torque, but there were no differences between groups on knee flexion peak torque. The results of this preliminary study suggest that carefully constructed full-range RT regimens can improve flexibility as well as the typical SS regimens employed in conditioning programs. Because of the potential practical significance of these results to strength and conditioning programs, further studies using true experimental designs, larger sample sizes, and longer training durations should be conducted with the aim of confirming or disproving these results.

Influence of chronic stretching on muscle performance: Systematic review.

Type of study: systematic review

Number of citations: 62

Year: 2017

Authors: D. M. Medeiros, C. Lima

Journal: Human movement science

Journal ranking: Q2

Key takeaways: Chronic stretching may improve muscle performance in functional tests and isotonic contractions, but not in isometric contractions.

Acute Effects of Stretching on Flexibility and Performance: A Narrative Review

Type of study: literature review

Number of citations: 28

Year: 2019

Authors: Camila D. Lima, C. V. Ruas, David G. Behm, L. Brown

Journal: Journal of Science in Sport and Exercise

Journal ranking: Q2

Key takeaways: Prolonged static stretching and PNF techniques can increase flexibility but may impair muscle force and power output without a full warm-up.

Abstract: Passive and active stretching techniques have been shown to increase both chronic and acute range of motion (ROM). Acute ROM improvements can be countered by decreases in muscle performance, primarily after prolonged static stretching (SS) and proprioceptive neuromuscular facilitation (PNF) techniques when not incorporated into a full warm up procedure. In contrast, ballistic stretching and dynamic stretching techniques typically induce either an increase or no change in muscular force and power. This review explores studies that have investigated stretching responses on ROM, muscle functionality and performance. Collectively, the literature demonstrates that prolonged acute SS and PNF stretching can elicit the greatest changes in flexibility, but without additional dynamic activities (i.e. full warm up) can induce neuromuscular force and power output impairments, while increasing ROM and some sports specific performance. Muscle response to stretching may be determined by the manipulation of confounding variables such as duration, population, volume, test specificity and frequency. An increased dosage of some of these variables during stretching in isolation, augments ROM increases while attenuating muscle force output, except for stretching intensity which may lead to similar responses. Populations with high flexibility may have positive effects from stretching when tested on their sport specific performance, while general population may suffer greater negative effects. Not controlling these variables during stretching protocols may lead to misleading information regarding its effects on muscle performance.

Flexibility Exercises and Performance

Type of study:

Number of citations: 6

Year: 2016

Authors: B. Bushman

Journal: ACSM's Health & Fitness Journal

Journal ranking: brak

Key takeaways: Stretching exercises can improve flexibility and range of motion, but may cause short-term performance impairments.

Abstract: Q: What is the value of stretching? Does stretching impact subsequent performance and, in particular, performance related to muscle strength and power? A: The American College of Sports Medicine (ACSM) states, 'For most adults, an exercise program including aerobic, resistance, flexibility, and neuromotor exercise training is indispensable to improve and maintain physical fitness and health' (1). Health and fitness benefits are well documented for cardiorespiratory endurance and resistance training (1,5,16). As a result, both aerobic fitness and muscular fitness exercises are included within the goals for Healthy People 2020. Target goals are for 47.9% of U.S. adults to be engaging in recommended amounts of aerobic activity and 24.1% to be engaging in muscular-strengthening activities (17). As a country, the most current report is encouraging, with targeted goals having been attained in these two areas (17). Although a goal related to flexibility exercises was included in the prior Healthy People 2010 objectives, the objective 22-5 related to flexibility (i.e., 'Increase the proportion of adults who perform physical activities that enhance and maintain flexibility') has been 'archived' (i.e., no longer included in 2020 Healthy People) (18). However, this is not to imply that flexibility exercises are not valued. The 2008 Physical Activity Guidelines for Americans states 'Flexibility is an important part of physical fitness…Stretching exercises are effective in increasing flexibility, and thereby can allow people to more easily do activities that require greater flexibility. For this reason, flexibility activities are an appropriate part of a physical activity program, even though they have no known health benefits and it is unclear whether they reduce risk of injury. Time spent doing flexibility activities by themselves does not count toward meeting the aerobic or muscle-strengthening guidelines' (16). Although flexibility may not impact health indicators as shown with aerobic or muscular fitness, stretching exercises should be considered as a valuable component of a complete exercise program. FLEXIBILITY EXERCISE RECOMMENDATIONS AND CONSIDERATIONS ACSM provides this simple definition of flexibility: 'Flexibility is the ability to move a joint through its complete ROM [range of motion]' (1). Many factors impact ROM, including distensibility of the joint capsule, adequate warm-up, muscle viscosity, and tightness of ligaments and tendons (1). The ability to fully use one's ROM plays a role in day-to-day activities (e.g., reaching, bending, turning) as well as athletic endeavors. The value of flexibility may be brought to full attention when a loss of range of motion occurs. Consider the impact of restricting ROM with poor posture, picturing the forward rounding of the shoulders of an office worker constantly hunched over a computer screen. Similarly, aging results in a loss of flexibility (5). Neglecting to spend time focused on flexibility can result in an avoidable loss of ROM. Instead, flexibility exercises should be included as part of an overall exercise program as a proactive way to maintain, or even improve, ROM. Flexibility exercises used to improve ROM can take a number of forms, including the following (1): static stretching (stretch and then hold the final position for a given time) ○ active static stretching (holding position by contraction of agonist muscle(s)) ○ passive static stretching (holding position with no involvement of agonist muscles, may use partner or stretching aid) dynamic stretching (stretch with slow movement; progressively increase the range of motion through repeated movements) proprioceptive neuromuscular facilitation (isometric contraction is followed by a static stretch) ACSM guidelines point out the acute improvement in ROM around a joint after engaging in flexibility exercise and suggest chronic, or long-term, improvement can be realized with regular stretching for 3 to 4 weeks (1). Box 1 includes ACSM recommendations related to flexibility for adults (1). Box 2 includes some background information related to the impact of proprioceptors on the muscles' response to stretching (7).The general recommendations for flexibility exercises seem rather simple and straightforward, but there are aspects related to the specifics of a stretching routine worthy of consideration. In particular, questions have surfaced regarding the impact that the type of stretching, and timing of stretching, may have on performance. ACSM guidelines note that 'Stretching exercises may result in an immediate, short-term decrease in muscle strength, power, and sports performance after stretching, with the negative effect particularly apparent when strength and power is important to performance' (1). Acknowledging that this is an area of ongoing research, ACSM suggests including flexibility exercises as a stand-alone activity or at the end of a training session (aerobic or resistance training) especially for exercises and sports in which strength and power are key elements (1). This recommendation reflects the positive chronic impact of stretching on ROM while recognizing concerns related to the acute changes in the muscles in the short term that may impact performance. The following section will explore some of the recent research and reviews on this topic that may be useful in developing individual stretching routines. FLEXIBILITY AND PERFORMANCE Increases in joint ROM seen with static stretching are associated with neural and viscoelastic aspects. Specifically, there are decreases in neural activity (motor neuron excitability decreases) and decreases in muscle stiffness (or conversely, increases in muscle compliance) (10). These result in greater ROM and freer movement, both desired outcomes of stretching. However, because of these changes, stretching may induce acute strength loss, with some suggesting this likely is due to neural aspects (10), whereas others note decreases in stiffness of the muscle-tendon unit (11,14). Research in this area is diverse and difficult to summarize. Moving from controlled laboratory protocols into the reality of a performance environment introduces a number of potentially confounding variables. Challenges arise in understanding how, and to what extent, stretching activities impact performance. A small decrement in performance may not be an issue for a recreational exerciser whereas the same minor change may greatly impact outcomes for an elite competitor (3). Many factors come into play when looking at research studies, including type of stretch, total duration of stretching, hold time of individual stretches, how strength is measured (and at what muscle length), and the timeframe between stretching and strength measures. To extend findings from controlled research settings into actual athletic endeavors adds even more questions. For example, stretching activities usually are not done in isolation but typically are combined with other warm-up activities and sport-specific drills (10). A small selection of studies are included in Box 3. This is by no means a comprehensive list, but it is intended to demonstrate how individual studies each add to the body of knowledge. These insights ultimately must be considered within the bigger picture, including other research. A number of summary articles and research reviews have been published. Some highlights from these review articles follow.Recent reviews have noted acute reductions in muscle performance including maximal strength, power, speed-dependent performance (9), maximal muscle strength, and explosive performance (14) because of static stretching. However, stretch duration seemed to play a role. One review noted the smallest negative impact when stretch durations were less than 45 seconds (but still a negative effect) (14), whereas another review found that no decrements in performance occurred when total duration of static stretches was less than 45 seconds, and moderate effects were found for durations of more than a minute (9). A more recent review confirmed moderate performance impairment (less than 5%) when stretching is done within minutes before measurement and noted the dose-response relationship with longer-duration static stretches (60 seconds or more) having greater effects than shorter-duration stretches (3). Even though the impairment is moderate, authors point out that for competitive endeavors, this might be 'practically relevant' (3). For the recreational exerciser, these mild alterations likely are not meaningful. With an awareness of potential concerns related to static stretching, many athletes turned to dynamic stretching. Once again, pros and cons need to be considered. A recent review reported an overall 1.3% improvement in performance with dynamic stretching, proposing that benefits observed may be because of warming up of the muscles (elevation of core temperature), similarity of movement between the dynamic stretching and the exercise performance, and increase in central drive (neural mechanism) (3). This supports a prior review in which dynamic stretching did not seem to have a negative acute impact on performance, and half the studies reported improvements (8). The researchers did point out that the benefits in ROM improvements with dynamic stretching must be balanced with the potential of such activities causing fatigue (8). Proprioceptive neuromuscular facilitation (PNF) is another method of stretching, but may be less common in many settings because of the need for a partner, the uncomfortable nature of the method, and potential for greater muscle damage when muscles contract when in a highly stretched position (3). In general, PNF results in small-to-moderate reductions in performance immediately after stretching, which, as noted with static stretching, may be of limited practical importance for the recreational exercisers whereas being worthy of consideration for competitive athletes (3). With the potential negative acute effect of stretching on strength and performance, one might question the value of flexibility exercises. With regard to acute effects, stretching is reported to improve economy of motion (13) as well as potential injury reduction in sports with sprint running (as opposed to overuse injuries as reported with endurance running activity and military training) (3). One research review noted the chronic effects of stretching, increasing ROM through time, as a benefit to performance involving stretch-shortening cycles (e.g., sprints, vertical jump, jump length, running tasks) (8). In another summary article, the benefits of regular stretching through time include increases in force and power (ranging from 2% to 5%) as evidenced in isometric contractions, isokinetic torque, and jump height as well as improvements in sprint running (13). One additional consideration is the impact of preactivity stretching on subsequent risk of injury. The research is not definitive with regard to the potential of stretching to impact injury risk. Study design is a challenge when trying to identify the influence of stretching, rather than other aspects of warm-up or training, on muscle strains (10). Risk factors that add to the difficulty in determining the role of stretching in preventing muscle strains are age, prior injury, and muscle weakness (10). Some studies show the benefits of stretching whereas others show no impact; however, no studies examined in a recent review found stretching to increase acute injury risk (3). Examination of review articles (see reference list at the end of this article) can be very helpful in gaining insights, but, ultimately, the decision to include flexibility exercises before exercise must be made on an individual basis. Some factors include one's level of flexibility, type of activity (e.g., power, speed, strength), ROM requirements for the activity, and performance aspects. If limited ROM impacts one's ability to carry out the movements required in the target exercise, mild impairments in strength/power might be outweighed by the benefits to be gained by an increased ROM achieved with stretching. Conversely, if ROM is already sufficient, and the activity requires force and power, then shifting flexibility exercises postactivity or in a separate training session may be preferred. Consider these examples in which the decision regarding use of preactivity stretching differs (13): An elite athlete with an established excellent level of flexibility whose sport requires quick movements and force development (e.g., soccer player) → likely would not recommend stretching before activity to avoid any potential reduction in force development. A recreational competitor with poor flexibility whose sport requires full ROM (e.g., martial arts, dance) → stretching before activity would be recommended to improve performance (an ongoing stretching program may result in improvements in flexibility, at which time whether to stretch before competition may need to be reexamined). For an individual engaging in a general exercise program to improve health and fitness, considerations include current flexibility, how ROM impacts the planned activity, and potential benefits (e.g., injury reduction). Because this is still an active and evolving area of research, ACSM Guidelines state, '…it is reasonable based on the available evidence to recommend when feasible, individuals engaging in a general fitness program perform flexibility exercises after cardiorespiratory or resistance exercise — or alternatively — as a stand-alone program' (1). CONCLUSIONS Flexibility exercises are recommended as part of a complete exercise program along with cardiorespiratory exercise, resistance training, and neuromotor exercise training. Although chronic improvements in ROM are possible with a regular stretching program, concerns have been raised related to the acute impact of stretching on subsequent strength and power performance. Although far from definitive, shifting stretching exercises from preactivity to postactivity may be an option to consider, or including flexibility exercises as a stand-alone program to reap the benefits of chronic adaptations.