Effects of different stretching methods on speed and agility performance in young tennis 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 ).

Change-of-Direction Speed Assessments and Testing Procedures in Tennis: A Systematic Review

ABSTRACT

Schneider, C, Rothschild, J, and Uthoff, A. Change-of-direction speed assessments and testing procedures in tennis: a systematic review. J Strength Cond Res 37(9): 1888-1895, 2023-Change-of-direction speed (CODS) plays an essential role in tennis match play, and CODS performance is, therefore, commonly assessed and monitored in tennis players. Thus, the aim of this systematic review was to describe test characteristics, performance metrics, test-retest reliability, construct validity, and test outcomes of tests that are used to assess CODS in tennis players. A literature search conducted on PubMed and SPORTDiscus yielded 563 results. After applying the eligibility criteria, a total of 27 studies were included in the present review. Ten unique CODS tests were identified. 505 test variations were most frequently used across all studies, and total time required to complete the test was the predominant performance metric investigated. Intrasession test-retest reliability ranged from "moderate" to "excellent." Intersession test-retest reliability as well as the effects of tennis performance, sex, and age on CODS performance were unclear given the subject demographics and the limited number of studies that investigated these aspects. In conclusion, most studies included CODS tests that exhibit longer COD entry and total distances but similar COD angles to those seen during tennis match play. All CODS tests have at least "moderate" intrasession test-retest reliability. However, to improve CODS assessment methods and to increase our current understanding of CODS performance in tennis players, there is a need to conduct more research on the intersession test-retest reliability, construct validity, and the effects of sex, age, and tennis performance and to investigate other performance metrics that might provide additional insights into CODS (e.g., phase-specific performance variables).

The Effect on Flexibility and a Variety of Performance Tests of the Addition of 4 Weeks of Soleus Stretching to a Regular Dynamic Stretching Routine in Amateur Female Soccer Players

The purpose of this study was to investigate the effects of 4 weeks of soleus stretching on ankle flexibility and dynamic balance, as well as selected monitoring and performance tests in soccer. Forty-five healthy female soccer players were randomly divided into a regular stretching group, a regular stretching group with soleus stretching, and a control group. Dynamic stretching protocols were performed for 4 weeks during three sessions per week as part of routine exercises. The regular group stretched three muscle groups (i.e., gastrocnemius, quadriceps, and hamstrings), while the regular + soleus group also stretched the soleus muscle. Before and after the stretching intervention, the ankle range of motion test, Y-balance test, drop jump test, dynamic knee valgus test, and Illinois Agility Running Test were performed. Ankle ROM, Y-balance, and DJ significantly improved in both intervention groups compared to controls. Only the regular + soleus group showed improvement in the Illinois Agility Running Test. Additionally, athletes performing the additional soleus stretching had greater improvements in ankle ROM and DJ but not in DKV or Y-balance. The results showed that adding soleus stretching into regular protocols can provide benefits for female soccer players in terms of performance parameters.

METHODS OF CORE STRENGTH TRAINING IN COLLEGE TENNIS PLAYERS

ABSTRACT Introduction Core strength training is essential for maintaining postural stability and explosive movement support, typical of tennis players. It has been proven that core strength training improves the motor coordination of the athlete’s whole body. Therefore, it is essential to develop specific approaches to strengthen the core in tennis players. Objective Analyze the effect of core strength training in college tennis players. Methods Twenty college tennis players were selected and randomly divided into two groups: core strength training and general training. Comparative results of the experiment were statistically processed for analysis on the effect of core strength training versus general strength training. Results There is a big difference in the level of fitness indicators before and after 14 weeks of core strength training (P < 0.05). The average gain in training speed of the athletes in the experimental group was 8.24% versus 1.05% in the control group. Conclusion Core strength training can improve the physical fitness of tennis players. Complementary core strengthening training can favor performance in matches and competition results. Evidence level II; Therapeutic Studies - Investigating the results.

Effect of Exercise Training on Physical Fitness Among Young Tennis Players: A Systematic Review

Background

Physical fitness comprises both health- and skill-related components that have been shown to correlate with the competitive ability of the athletes. Competitive ability of the athletes is strongly related to the positive or poor characteristics of physical fitness. Additionally, the adolescent stage is critical for the development of physical fitness. Physical fitness training for young tennis players should receive more attention. However, the current literature is deficient in in-depth reviews of the effects of exercise training on the physical fitness of young tennis players.

Objective

This review is aimed to investigate the effects of exercise training on physical fitness among young tennis players.

Methods

From October 2020, a comprehensive search was undertaken in four electronic databases (SCOPUS, PubMed, EBSCOhost (SPORTDiscus), and CINAHL Plus) and also on Google Scholar and other sources of gray literature references. The methodological quality of included studies was assessed using the Physiotherapy Evidence Database scale and the over scientific evidence was determined using the best evidence synthesis (BES). This review included only studies that employed an experimental design to assess the physical fitness components of young tennis players.

Results

Nine articles on exercise training met all inclusion criteria and were included in this systematic review. The studies were of a high standard of quality. The research findings are relatively credible. The results indicated that speed (n = 8) and agility (n = 8) were the most often investigated performance characteristics in exercise training interventions with young tennis players, followed by power (n = 7), strength (n = 4), and flexibility (n = 1). Exercise training significantly increased the physical fitness of young tennis players in terms of speed and agility. There is a lack of evidence about strength and flexibility. Meanwhile, there is conflicting evidence regarding the effect on power, and yet there is no evidence regarding the effect of exercise training on endurance.

Conclusions

This systematic review established a compelling case for the beneficial effects of exercise training interventions on physical fitness in youngtennis players. The review identifies current research gaps (i.e., athlete gender, with a particular emphasis on female athletes) that should be addressed in future experimental studies.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero, identifier CRD 42020213145.