Acute Effects of a Static Vs. a Dynamic Stretching Warm-up on Repeated-Sprint Performance in Female Handball Players

What We Do Not Know About Stretching in Healthy Athletes: A Scoping Review with Evidence Gap Map from 300 Trials

BACKGROUND

Stretching has garnered significant attention in sports sciences, resulting in numerous studies. However, there is no comprehensive overview on investigation of stretching in healthy athletes.

OBJECTIVES

To perform a systematic scoping review with an evidence gap map of stretching studies in healthy athletes, identify current gaps in the literature, and provide stakeholders with priorities for future research.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and PRISMA-ScR guidelines were followed. We included studies comprising healthy athletes exposed to acute and/or chronic stretching interventions. Six databases were searched (CINAHL, EMBASE, PubMed, Scopus, SPORTDiscus, and Web of Science) until 1 January 2023. The relevant data were narratively synthesized; quantitative data summaries were provided for key data items. An evidence gap map was developed to offer an overview of the existing research and relevant gaps.

RESULTS

Of ~ 220,000 screened records, we included 300 trials involving 7080 athletes [mostly males (~ 65% versus ~ 20% female, and ~ 15% unreported) under 36 years of age; tiers 2 and 3 of the Participant Classification Framework] across 43 sports. Sports requiring extreme range of motion (e.g., gymnastics) were underrepresented. Most trials assessed the acute effects of stretching, with chronic effects being scrutinized in less than 20% of trials. Chronic interventions averaged 7.4 ± 5.1 weeks and never exceeded 6 months. Most trials (~ 85%) implemented stretching within the warm-up, with other application timings (e.g., post-exercise) being under-researched. Most trials examined static active stretching (62.3%), followed by dynamic stretching (38.3%) and proprioceptive neuromuscular facilitation (PNF) stretching (12.0%), with scarce research on alternative methods (e.g., ballistic stretching). Comparators were mostly limited to passive controls, with ~ 25% of trials including active controls (e.g., strength training). The lower limbs were primarily targeted by interventions (~ 75%). Reporting of dose was heterogeneous in style (e.g., 10 repetitions versus 10 s for dynamic stretching) and completeness of information (i.e., with disparities in the comprehensiveness of the provided information). Most trials (~ 90%) reported performance-related outcomes (mainly strength/power and range of motion); sport-specific outcomes were collected in less than 15% of trials. Biomechanical, physiological, and neural/psychological outcomes were assessed sparsely and heterogeneously; only five trials investigated injury-related outcomes.

CONCLUSIONS

There is room for improvement, with many areas of research on stretching being underexplored and others currently too heterogeneous for reliable comparisons between studies. There is limited representation of elite-level athletes (~ 5% tier 4 and no tier 5) and underpowered sample sizes (≤ 20 participants). Research was biased toward adult male athletes of sports not requiring extreme ranges of motion, and mostly assessed the acute effects of static active stretching and dynamic stretching during the warm-up. Dose-response relationships remain largely underexplored. Outcomes were mostly limited to general performance testing. Injury prevention and other effects of stretching remain poorly investigated. These relevant research gaps should be prioritized by funding policies.

REGISTRATION

OSF project ( https://osf.io/6auyj/ ) and registration ( https://osf.io/gu8ya ).

Impact of warm-up methods on strength-speed for sprinters in athletics: a mini review

In athletics, achieving peak performance during competitions is crucial. Warm-up strategies play a crucial role in optimizing the strength-speed performance of sprinters in athletics, especially tailored to the physiological demands of speed events. The need to balance flexibility, prevent injuries, and enhance power output makes the selection of an effective warm-up protocol essential. This narrative review examines different warm-up methods used by athletes and their effects on strength-speed in sprinters in athletics. The main findings indicate that Foam Rolling (FR), Isometric Exercises and Pre-Competitive Massages have no significant effects on sprint performance. Static stretching and prolonged Pre-Competitive Massages have negative impacts on strength and power. The Vibration Platform enhances step length, step rate and running velocity, jump height and total number of jumps performed in a 30-s period in non-experienced sprinters. Eccentric Exercise increases vertical force, Post-Activation Potentiation (PAP) demonstrates a reduction in 100-meter time and short-term improvement in vertical and horizontal jumps. Blood Flow Restriction (BFR) significantly improving jump height and flight time. Various warm-up methods have been identified, some focusing on flexibility, others potentially detrimental, and some enhancing strength and power. Implementing effective warm-ups, particularly those promoting strength and power, poses a challenge for coaches seeking reliable alternatives to boost performance.

Effects of whole-body cryotherapy and static stretching are maintained 4 weeks after treatment in most patients with chronic fatigue syndrome

In the previous study, whole-body cryotherapy (WBC)+static stretching (SS) has been shown to reduce the severity of some symptoms in Chronic Fatigue Syndrome (CFS) noted just after the therapy. Here we consider the effects of treatment and explore the sustainability of symptom improvements at four weeks (one-month) follow-up. Twenty-two CFS patients were assessed one month after WBC + SS programme. Parameters related to fatigue (Chalder Fatigue Questionnaire (CFQ), Fatigue Impact Scale (FIS), Fatigue Severity Scale (FSS)), cognitive function (Trial Making test part A and B (TMT A and TMT B and its difference (TMT B-A)), Coding) hemodynamic, aortic stiffness (aortic systolic blood pressure (sBP aortic)) and autonomic nervous system functioning were measured. TMT A, TMT B, TMT B-A and Coding improved at one month after the WBC + SS programme. WBC + SS had a significant effect on the increase in sympathetic nervous system activity in rest. WBC + SS had a significant, positive chronotropic effect on the cardiac muscle. Peripheral and aortic systolic blood pressure decreased one month after WBC + SS in comparison to before. Effects of WBC + SS on reduction of fatigue, indicators of aortic stiffness and symptoms severity related to autonomic nervous system disturbance and improvement in cognitive function were maintained at one month. However, improvement in all three fatigue scales (CFQ, FIS and FSS) was noted in 17 of 22 patients. In addition, ten patients were treated initially but they were not assessed at 4 weeks, and are thus not included in the 22 patients who were examined on follow-up. The overall effects of WBC + SS noted at one month post-treatment should be interpreted with caution.

Dynamic and static stretching on hamstring flexibility and stiffness: A systematic review and meta-analysis

INTRODUCTION

Hamstring injuries are one of the most common types of damage in sports. Insufficient flexibility and high stiffness are important reasons for it. Stretching is often used in warm-up activities before exercises to increase flexibility, among which dynamic stretching (DS) and static stretching (SS) are the most widely used. The effects of these two stretching techniques on the flexibility or stiffness of the hamstring still need to be clarified.

OBJECTIVE

This study aimed to compare the short-term, medium-term, and long-term effects of DS and SS on improving hamstring flexibility and stiffness via a meta-analysis of RCTs.

METHODS

RCTs were identified from PubMed, Cochrane Library, Web of Science, and PEDro from inception to July 28, 2022. The methodological quality was evaluated using the PEDro scale. The mean difference and 95% confidence interval of the outcome variables before and after stretching were calculated and the extracted data were quantitatively processed using a random or fixed effects model.

RESULTS

A total of 27 RCTs and 606 participants were included. In terms of improving the ROM of the hamstring, there was no significant difference in the acute (MD, -0.70, 95% CI, -1.54 to 0.14; Z = 1.63, P > 0.05) and sub-acute effects (MD, 1.71, 95% CI, -2.80 to 6.22; Z = 0.74, P > 0.05) between a single bout of SS and DS, while the acute (MD, -5.13, 95% CI, -7.65 to -2.61; Z = 3.99, P < 0.05) and sub-acute effects (MD, -5.30, 95% CI, -6.33 to -4.27; Z = 10.04, P < 0.05) of multiple bouts of SS was superior to DS; There was no significant difference in the medium-term effect between the two stretching techniques (MD, 3.48, 95% CI, -2.57 to 9.53; Z = 1.13, P > 0.05), but the long-term effect of SS was better than DS (MD, - 10.40, 95% CI, -10.97 to -9.83; Z = 35.57, P < 0.05). Regarding the length of the hamstring, the acute (MD, -0.41, 95% CI, -1.09 to 0.26; Z = 1.20, P > 0.05) and sub-acute effects (MD, -0.73, 95% CI, -1.69 to 0.22; Z = 1.51, P > 0.05) of a single bout of DS and SS were similar. Two studies have compared the effects on hamstring stiffness, with one showing similar effects, and the other showed that DS was superior to SS. One study showed no difference in the magnitude of change in improving passive torque. No studies explored the effect of DS and SS on hamstring myofascial length. Only one study demonstrated no significant difference in hamstring thickness.

CONCLUSIONS

A single bout of DS and SS have similar short-term effects in improving hamstring ROM and length, while multiple bouts of SS can significantly improve hamstring ROM compared to DS. DS and SS showed similar effects on hamstring myofascial length.

Potential Effects of Dynamic Stretching on Injury Incidence of Athletes: A Narrative Review of Risk Factors

The use of dynamic stretching as a replacement for static stretching in the warm-up is widespread based on the reports of static stretching-induced performance impairments. While acute and chronic static stretching has been reported to reduce musculotendinous injuries, especially with explosive and change of direction actions, the influence of dynamic stretching on injury incidence lacks a similar volume of literature for acute and chronic responses. It was the objective of this narrative review to examine the acute and training effects of dynamic stretching on injury incidence and possible moderating variables such as dynamic stretching effects on range of motion, strength, balance, proprioception, muscle morphology, and psycho-physiological responses. One study demonstrated no significant difference regarding injury incidence when comparing a dynamic stretching-only group versus a combined dynamic stretching plus static stretching group. The only other study examined functional dynamic stretching training with injured dancers and reported improved ankle joint stability. However, several studies have shown that dynamic activity with some dynamic stretching exercises within a warm-up consistently demonstrates positive effects on injury incidence. Regarding moderating variables, while there is evidence that an acute bout of dynamic stretching can enhance range of motion, the acute and training effects of dynamic stretching on strength, balance, proprioception, and musculotendinous stiffness/compliance are less clear. The acute effects of dynamic stretching on thixotropic effects and psycho-physiological responses could be beneficial for injury reduction. However, the overall conflicting studies and a lack of substantial literature compared with SS effects points to a need for more extensive studies in this area.

Effects of traditional stretching versus self-myofascial release warm-up on physical performance in well-trained female athletes

OBJECTIVE

The purpose of this study was to compare the acute effects of self-myofascial release (SMR) versus traditional stretching used as a part of warm-up on physical performance in well-trained female athletes.

METHODS

Twenty-three participants (age, 21.8±1.73 years; experience in sport, 114.8±30.5 months) were recruited. Isokinetic peak torque and muscle endurance ratio were measured during knee extension and flexion at 60°/s and 180°/s. Jump height, reactive strength index, and leg stiffness were measured using a jump mat during a counter-movement jump. Hamstring flexibility was measured using a sit-and-reach test. Three interventions were performed by all athletes randomly within 72 hours intervals.

RESULTS

The jump height and hamstring flexibility test scores improved significantly more after dynamic stretching (DS) as compared to SMR and static stretching (SS). The DS and SMR exercises were more effective than the SS exercises in terms of right and left knee muscle isokinetic strength both at 60°/s, and 180°/s. With regard to keeping muscular endurance ratio (%), SS exercises were found more effective than DS and SMR exercises for only the right knee at 180°/s, but not left knee muscle.

CONCLUSION

Dynamic stretching and SMR showed better flexibility, strength, and jump performance than SS. Trainers and players may replace SS with DS and SMR to acutely improve muscle power, strength, and flexibility.

Combination of whole body cryotherapy with static stretching exercises reduces fatigue and improves functioning of the autonomic nervous system in Chronic Fatigue Syndrome

BACKGROUND

The aim of this study was to explore the tolerability and effect of static stretching (SS) and whole body cryotherapy (WBC) upon fatigue, daytime sleepiness, cognitive functioning and objective and subjective autonomic nervous system functioning in those with Chronic Fatigue Syndrome (CFS) compared to a control population.

METHODS

Thirty-two CFS and eighteen healthy controls (HC) participated in 2 weeks of a SS + WBC programme. This programme was composed of five sessions per week, 10 sessions in total.

RESULTS

A significant decrease in fatigue was noted in the CFS group in response to SS + WBC. Some domains of cognitive functioning (speed of processing visual information and set-shifting) also improved in response to SS + WBC in both CFS and HC groups. Our study has confirmed that WBC is well tolerated by those with CFS and leads to symptomatic improvements associated with changes in cardiovascular and autonomic function.

CONCLUSIONS

Given the preliminary data showing the beneficial effect of cryotherapy, its relative ease of application, good tolerability, and proven safety, therapy with cold exposure appears to be an approach worth attention. Further studies of cryotherapy as a potential treatment in CFS is important in the light of the lack of effective therapeutic options for these common and often disabling symptoms.

Acute effect of a static- and dynamic-based stretching warm-up on standing long jump performance in primary schoolchildren

The aim of the present study was to compare the acute effect of a static- vs dynamic-based stretching warm-up on standing long jump (SLJ) performance in primary schoolchildren. The sample was composed of 76 schoolchildren, 43 girls and 33 boys, aged 9–10 years old from three fourth-grade classes of Primary Education. The three groups were cluster-randomly assigned to the control (CG), static (SG) or dynamic (DG) groups. All the schoolchildren performed a standardized warm-up consisting of mobility exercises (five minutes), jogging (five minutes) and the SLJ test. Afterwards the CG schoolchildren received jump theory (eight minutes), the SG performed static stretching (eight minutes) and the DG performed dynamic-bounces stretching (eight minutes). Afterwards, all of them performed the SLJ test again. The results of the one-way ANOVA (F_2,73 = 34.184; p < 0.001; η²p = 0.484), followed by the pairwise comparisons with the Bonferroni adjustment, showed that the DG students (M_Δ = 11.07, SE = 1.42) made a significant statistical improvement in their SJL levels compared with the CG (M_Δ = -3.00, SE = 1.89; p < 0.001, d = 1.51) and SG students (M_Δ = -1.85, SE = 0.67; p < 0.001, d = 1.38). However, statistically significant differences between the CG and SG students were not found (p > 0.05, d = 0.12). The dynamic-bouncing stretch as a final part of a warm-up improves explosive strength performance in primary schoolchildren, and seems to be a good option before carrying out explosive strength activities of the lower body.

Changes in the Allostatic Response to Whole-Body Cryotherapy and Static-Stretching Exercises in Chronic Fatigue Syndrome Patients vs. Healthy Individuals

This study represents a comparison of the functional interrelation of fatigue and cognitive, cardiovascular and autonomic nervous systems in a group of Chronic Fatigue Syndrome (CFS) patients compared with those in healthy individuals at different stages of analysis: at baseline and after changes induced by whole-body cryotherapy (WBC) combined with a static-stretching (SS) program. The study included 32 patients (Fukuda criteria) and 18 healthy controls. Fatigue, cognitive, cardiovascular and autonomic function and arterial stiffness were measured before and after 10 sessions of WBC with SS. In the patients, a disturbance in homeostasis was observed. The network relationship based on differences before and after intervention showed comparatively higher stress and eccentricity in the CFS group: 50.9 ± 56.1 vs. 6.35 ± 8.72, p = 0.002, r = 0.28; and 4.8 ± 0.7 vs. 2.4 ± 1, p < 0.001, r = 0.46, respectively. Before and after intervention, in the CFS group increased fatigue was related to baroreceptor function, and baroreceptor function was in turn related to aortic stiffness, but no such relationships were observed in the control group. Differences in the network structure underlying the interrelation among the four measured criteria were observed in both groups, before the intervention and after ten sessions of whole cryotherapy with a static stretching exercise.

Return to football training and competition after lockdown caused by the COVID-19 pandemic: medical recommendations

The lockdown caused by the COVID-19 pandemic represents a great unknown regarding the physiological changes induced in elite football players. Although it will differ from country to country, the return to sport for professional football players will follow a forced lockdown never experienced and longer than the normal annual season break. Moreover, in addition to an obvious decrease in performance, the lockdown will possibly lead to an increase of the injury risk. In fact, preseason is always a period with a specific football injury epidemiology, with an increase in the incidence and prevalence of overuse injuries. Therefore, it seems appropriate to recommend that specific training and injury prevention programmes be developed, with careful load monitoring. Training sessions should include specific aerobic, resistance, speed and flexibility training programmes. The aerobic, resistance and speed training should respect some specific phases based on the progressiveness of the training load and the consequent physiological adaptation response. These different phases, based on the current evidence found in the literature, are described in their practical details. Moreover, injury prevention exercises should be incorporated, especially focusing on overuse injuries such as tendon and muscle lesions. The aim of this paper is to provide practical recommendations for the preparation of training sessions for professional footballers returning to sport after the lockdown.

Repeated Sprint Ability Demands in U16 to U19 Highly Trained Handball Players Concerning Playing Position

The aim of the study was to determine anaerobic capacity and characterize changes in repeated sprint ability (RSA) within youth elite handball players. For this study, 142 male athletes (17.1 ± 0.9 years) were recruited from a handball sports high school and performed the RSA test on a cycle ergometer, including five 6 s all-out efforts separated by 24 s passive breaks. Maximal (P_max) and mean (P_mean) power, highest (W_max), and total work (W_tot) as well as power (P_dec) and work (W_dec) decrement were measured. Significant differences in RSA were noted in relation to age (greater values of P_max, P_mean, W_tot, W_dec, and P_dec in U19 than U17 as well as greater values of P_max, W_tot, W_max, W_dec, and P_dec in U19 than U16 (p < 0.05)) and playing position (wing players had greater W_tot than pivot, 269 vs. 243 (J/kg) (p < 0.05), and wing players differed significantly in absolute and relative power from athletes of other positions). RSA depends on playing position and age in groups of youth handball players and the RSA test can be helpful in the selection of athletes for a playing position. The article introduces normative values for elite youth handball players, empowering coaches in the evaluation of anaerobic abilities and selection.