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.

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.

The effects of different durations of static stretching within a comprehensive warm-up on voluntary and evoked contractile properties

Evidence for performance decrements following prolonged static stretching (SS) has led to a paradigm shift in stretching routines within a warm-up. Rather than SS, dynamic stretching (DS) and dynamic activity (DA) have replaced SS within warm-up routines. The objective of the present study was to compare the effect of differing lower limb SS durations (30 [SS30s], 60 [SS60s] or 120 s [SS120s] of SS per muscle group or no-stretch control) within a comprehensive warm-up protocol consisting of aerobic activity, DS and DA. Sixteen male participants completed the four stretching conditions in a randomized order, after a 5-min low-intensity (cycle) warm-up and before a DS/DA component on separate days. Tests included passive hip and knee ranges of motion (ROM), maximum voluntary knee extensor/flexor force, force produced at 100 ms (F100), vertical jump height and evoked knee extensor contractile properties. For hip flexion (hamstrings) ROM, SS120s provided the largest increase (5.6-11.7%) followed by SS60s (4.3-11.4%), control (4.4-10.6%) and SS30s (3.6-11.1%). For knee flexion (quadriceps) ROM, SS30s provided the largest increase (9.3-18.2%) followed by SS120s (6.5-16.3%), SS60s (7.2-15.2%) and control (6.3-15.2%). There were decreases in quadriceps F100 following SS in SS120s (29.6%) only. There were increases in vertical jump performance in the control (6.2%), SS60s (4.6%) and SS30s (3.3%). While 120 s SS per muscle increased ROM, even within a comprehensive warm-up routine, it also elicited notable performance decrements. However, moderate durations of SS were observed to improve ROM whilst either having negligible or beneficial (but not detrimental) effects on specific aspects of athletic performance.

Pre- and Post-Activity Stretching Practices of Collegiate Athletic Trainers in the United States

Popp, JK, Bellar, DM, Hoover, DL, Craig, BW, Leitzelar, BN, Wanless, EA, and Judge, LW. Pre- and post-activity stretching practices of collegiate athletic trainers in the United States. J Strength Cond Res 31(9): 2347-2354, 2017-The aim of the study was to investigate the knowledge and practices of collegiate-certified athletic trainers (ATs) in the United States. Participants (n = 521) were provided an overview of the study and a hyperlink to a web-based survey. The "pre- and post-activity practices in athletic training questionnaire" consisted of demographic items and elements to measure knowledge and practices related to pre- and post-activity stretching routines. In previous studies, the survey demonstrated construct validity, α = 0.722. Pearson chi-square test was used to evaluate goodness of fit, and kappa was calculated to measure agreement between items. Only 32.2% of ATs recommended dynamic stretching (DS) to be performed pre-activity, whereas a larger percentage (42.2%) recommended a combination of static stretching (SS) and DS. Athletic trainers reported that only 28.0% of athletes are performing DS before activity. Conversely, 60.6% of collegiate ATs recommended SS postexercise, and 61.0% of athletes agree and perform after workout SS (κ = 0.761, p < 0.001). Collegiate ATs seem to underuse the current research evidence, which indicates that DS is more beneficial than SS when used pre-activity, and ATs continue to regularly incorporate SS in their pre-activity routines. However, there is evidence that collegiate ATs in the United States emphasize SS postactivity in a manner consistent with current research.

Complementing Warm-up with Stretching Routines: Effects in Sprint Performance

The present study aimed to examine the effects of using static or dynamic stretching added to the common warm-up routine for short sprint distances and to repeated sprint performance. In 3 different sessions, 16 college-age men (n=10) and women (n=6) performed one of 3 warm-ups followed by a 2×60 m dash sprint time trial (5 min of rest) in a counterbalanced design. The control warm-up consisted of 10 min of light-intensity running, and the 2 experimental warm-ups included a static or dynamic stretching routine (5 exercises) in the control warm-up. Performance (time) and physiological variables (tympanic temperature, heart rate) were monitored. In the first 60 m time trial, there were no differences between the 3 warm-ups tested ( F =0.21, p=0.73; η _p² =0.01), as opposed to that observed in the second ( F =7.04, p<0.01; η _p² =0.32). The participants were 1.7% faster after the static stretching warm-up compared with the control warm-up. The sum of the time performed in the 2 sprints emphasizes these results, with better performances after the static stretching warm-up than the control (1%) or dynamic stretching warm-up (0.7%). These results suggest that including a set of static or dynamic stretching exercises may enhance sprinting performance. The better performance in the second trial after the warm-up including static stretching suggests that this type of stretching may positively influence repeated sprint performance (<10 s sprint).

The Acute Effects of Static Stretching on Speed and Agility Performance Depend on Stretch Duration and Conditioning Level

Avloniti, A, Chatzinikolaou, A, Fatouros, IG, Avloniti, C, Protopapa, M, Draganidis, D, Stampoulis, T, Leontsini, D, Mavropalias, G, Gounelas, G, and Kambas, A. The acute effects of static stretching on speed and agility performance depend on stretch duration and conditioning level. J Strength Cond Res 30(10): 2767-2773, 2016-Although static stretching (SS) is an integral part of physical preparation before training and competition, its usefulness in regards to power performance improvement has been questioned. The aim of this study was to investigate the effect of 6 SS durations on speed and agility performance. According to a cross-over design, 34 trained men (age, 20.5 ± 1.4 years; height, 1.81 ± 0.2 m; weight, 77.2 ± 2.6 kg; body fat, 8.2 ± 2.6%) participated in a control session (no stretch) and 6 experimental conditions (10, 15, 20, 30, 40, and 60 seconds) performed in a randomized order. Performance in speed (10 and 20 m) and agility (T-test) was measured after the control and experimental conditions. Static stretching, consisting of stretches for hip extensors, hip adductors, knee extensors, knee flexors, and ankle sole flexors, was performed after light cardiovascular exercise (8 minutes). A 1-way repeated-measures analysis of variance showed that speed was improved only by SS of short duration (15/20 seconds), whereas agility remained unaffected by all SS trials. When participants' speed and agility level was taken into account, it was revealed that only those of moderate performance demonstrated an improved speed (in 15- and 20-second trials) and agility (in 10- and 15-second trials) performance. These results suggest that short-duration SS protocols induce an acute improvement of speed and agility performance, whereas longer-duration SS protocols have neither positive nor negative effect. Furthermore, it seems that individuals of lower speed and agility performance level are more likely to benefit by a short-duration SS protocol.

The effects of static stretching on speed and agility: One or multiple repetition protocols?

Although static stretching (SS) is utilized during warm-up before training and competition, the results about its effects on performance remain controversial. We examined whether performing a stretch of short-to-moderate duration (<60 sec) in a single repetition produces a similar or different effect on speed and agility performance from the effect which is produced while performing the same stretch in multiple repetitions of the same total duration. According to a repeated measurement design, 40 trained males were randomly assigned to either (1) a single repetition group or (2) a multiple repetition group. The participants in each group performed five trials: a control trial (no stretches were performed) and four experimental trials of SS protocols consisting of five exercises performed at either 20 sec (2 × 10 in the second group), 30 sec (3 × 10 in the second group), 40 sec (4 × 10 in the second group) or 60 sec (6 × 10 in the second group) of total duration. A two-way repeated measures analysis of variance showed that the participants in both group improved their speed performance in response to the 20-sec trial, whereas agility remained unaffected. Data analysis also revealed that the repetition number did not affect speed and agility performance. These data suggest that SS of short duration (<30 sec) may actually improve acute speed performance, whereas SS of moderate duration may not hamper speed and agility performance. Moreover, the effects of SS protocols are related to the total duration of each exercise and not to the number of repetitions in which each exercise is performed.

Using a practical approach for determining the most effective stretching strategy in female college division I volleyball players

The purpose of this investigation was to quantify the effects that a practical bout of static stretching (SS) and dynamic stretching (DS) has on maximal countermovement jump (CMJ) height across a time spectrum of 25 minutes in National Collegiate Athletic Association Division I varsity volleyball players. Eleven female varsity volleyball players (mean ± SD; age 20.00 ± 1.55 years; height 1.78 ± 0.08 m; mass 74.55 ± 12.18 kg) volunteered for this investigation. Three days of randomized experimental testing (SS, DS, control) were completed. The SS protocol consisted of stretching 7 muscle groups. The DS protocol consisted of the volleyball team's actual DS routine of equal duration (30 seconds) to SS. Poststretch performance measures of CMJ were determined at 1, 5, 15, and 25 minutes poststretch. Countermovement jump had an acute significant trial-by-time interaction, indicating that DS was found to produce significantly higher scores than the SS and control session at 1 and 5 minutes poststretch, but not at 15 and 25 minutes poststretch. Additionally, there was a timing interaction within trials where SS scores were significantly lower at 1 minute poststretch compared with 5 and 25 minutes poststretch, and DS scores were significantly higher at 1 and 5 minutes poststretch compared with 15 and 25 minutes poststretch. Athletes engaging in competitive power sports should continue to utilize their DS routine but may need to do so within 5 minutes before activity.

Effects of static and dynamic stretching on sprint and jump performance in boys and girls

The aim of this study was to investigate the acute effects of static (SS) and dynamic stretching (DS) on explosive power, flexibility, and sprinting ability of adolescent boys and girls and to report possible gender interactions. Forty-seven active adolescent boys and girls were randomly tested after SS and DS of 40 seconds on quadriceps, hamstrings, hip extensors, and plantar flexors; no stretching was performed at the control condition. Pretreatment and posttreatment tests examined the effects of stretching on 20-m sprint run (20 m), countermovement jump (CMJ) height, and sit and reach flexibility test. In terms of performance, SS hindered 20 m and CMJ in boys and girls by 2.5 and 6.3%, respectively. Dynamic stretching had no effect on 20 m in boys and girls but impaired CMJ by 2.2%. In terms of flexibility, both SS and DS improved performance with SS being more beneficial (12.1%) compared with DS (6.5%). No gender interaction was found. It can therefore be concluded that SS significantly negates sprinting performance and explosive power in adolescent boys and girls, whereas DS deteriorates explosive power and has no effect on sprinting performance. This diversity of effects denotes that the mode of stretching used in adolescent boys and girls should be task specific.

A comparison of self-administered proprioceptive neuromuscular facilitation to static stretching on range of motion and flexibility

Stretching is known to be an effective method for increasing range of motion. Proprioceptive neuromuscular facilitation (PNF) is a stretching technique that is often associated with a partner. The goal of this study was to examine the changes in hip range of motion (ROM) and hip, back and shoulder flexibility (HBSF) after an intervention of self-administered PNF vs. traditional static stretching. Nineteen healthy college-aged individuals (ages 19-25 years) completed the study. Participants were tested preintervention and postintervention for hip ROM and HBSF using a goniometer and sit-and-reach test, respectively. Interventions included static or self-PNF hamstring stretching 2 × 40 seconds on each leg for 6 weeks. Participants were randomly placed in a group, and upon completion of the intervention and a 1-week rest period, they repeated the process with the other intervention. Statistical analysis revealed that there was a significant difference (p < 0.01) in the change in hip ROM and HBSF between the static stretch and self-PNF group. Mean and SD changes in the hip ROM were -6.2 ± 6.6° vs. 0.6 ± 4.5° for the PNF and static groups, respectively (where a negative value indicates an increase in ROM) and 5.2 ± 3.3 cm vs. 2.0 ± 2.6 cm, respectively, for HSBF. In addition, significant improvements (using 99% confidence intervals) were found in the 2 measures after the PNF intervention but only in HBSF after the static stretching intervention. These results suggest that self-PNF can be used in place of static stretching, does not require a partner, and gives control of the stretching to the individual.

Effects of stretching on performances involving stretch-shortening cycles

BACKGROUND

Alongside its role in athletic conditioning, stretching has commonly been integrated in warm-up routines prior to athletic performance. Numerous studies have reported detrimental acute effects on strength following stretching. Consequently, athletes have been recommended to discontinue stretching as part of warm-ups. In contrast, studies indicate that chronic stretching performed as a separate bout from training or competition may enhance performance. However, the influence of stretching on complex performances has received relatively little attention.

OBJECTIVE

The purpose of this study was to review both the acute and chronic effects of stretching on performances involving the stretch-shortening cycle (SSC).

METHODS

A systematic search for literature was undertaken (January 2006-December 2012) in which only randomized controlled trials (RCTs) or studies with repeated measures designs were included. The Physiotherapy Evidence Database (PEDro) rating scale was used for quality assessment of the evidence.

RESULTS

The review included 43 studies, from which conflicting evidence emerged. Approximately half of the studies assessing the acute effect of static stretching reported a detrimental effect on performance, while the remainder found no effect. In contrast, dynamic stretching showed no negative effects and improved performance in half of the trials. The effect size associated with static and dynamic stretching interventions was commonly low to moderate, indicating that the effect on performance might be limited in practice. Factors were identified that might have contributed to the conflicting results reported across studies, such as type of SSC performance and carrying out dynamic activity between the stretching bout and performance. Few studies since 2006 have addressed the chronic effect of stretching on functional and sports performance. Although negative effects were not reported, robust evidence of the overall beneficial effects within current bibliographic databases remains elusive. Plausible mechanisms for the observed effects from stretching are discussed, as well as possible factors that may have contributed to contradictory findings between studies.

LIMITATIONS

Considerable heterogeneity in study design and methods makes comparison between studies challenging. No regression analysis of the contribution of different predictors to variation between trials had previously been performed. Hence, predictors had to be selected on the basis of a qualitative analysis of the predictors that seemed most influential, as well as being identified in previous narrative reviews.

CONCLUSION

Different types of stretching have differential acute effects on SSC performances. The recommended volume of static stretching required to increase flexibility might induce a negative acute effect on performances involving rapid SSCs, but the effect sizes of these decrements are commonly low, indicating that the acute effect on performance might be limited in practice. No negative acute effects of dynamic stretching were reported. For athletes that require great range of motion (ROM) and speed in their sport, long-term stretching successfully enhances flexibility without negatively affecting performance. Acute dynamic stretching may also be effective in inducing smaller gains in ROM prior to performance without any negative effects being observed.

Warm-ups for military fitness testing: rapid evidence assessment of the literature

INTRODUCTION

Warm-up exercises are commonly used before exercise as a method to physiologically prepare for strenuous physical activity. Various warm-up exercises are often implemented but without scientific merit and, at times, may be detrimental to performance.

PURPOSE/OBJECTIVE

To date, no systematic reviews have examined the effectiveness of warm-up exercises for military physical fitness test (PFT) or combat fitness test (CFT). The purpose of this rapid evidence assessment of the literature was to examine the quantity, quality, and effectiveness of warm-up exercises for PFT and identify those that might increase PFT and/or CFT scores, as reported in the literature.

METHODS

Literature searches of randomized controlled trials were performed across various databases from database inception to May 2011. Methodological quality of included studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) 50 criteria for randomized controlled trial designs, and studies were individually described. Subject matter experts summarized the results applicable or generalizable to military testing.

RESULTS

The search yielded a total of 1177 citations, with 37 fitting our inclusion criteria. Cardiovascular warm-ups increased sprint/running time, but dynamic stretching and dynamic warm-ups had the most positive outcome for the various exercise tests examined. Systematically, static stretching had no beneficial or detrimental effect on exercise performance but did improve range of movement exercises.

CONCLUSIONS

Selected warm-up exercise may increase PFT and possibly CFT scores. Further research is needed to investigate the efficacy of dynamic stretching and dynamic warm-ups.

Efeito agudo de exercícios de alongamento estático e dinâmico na impulsão vertical de jogadores de futebol

O objetivo deste estudo foi comparar o efeito agudo dos exercícios de alongamento estático e do alongamento dinâmico na impulsão vertical e amplitude do movimento de 22 jogadores de futebol profissional do sexo masculino. Observou-se que após a intervenção do alongamento dinâmico, o grupo experimental (n=13) apresentou um aumento significativo na impulsão vertical (p=0,002), enquanto que após o alongamento estático, não houve alteração significativa (p=0,343), assim como na condição sem alongamento (p>0,05). Com relação aos níveis de amplitude de movimento (n=13), não houve diferenças significativas no sentar e alcançar (p=0,263) nas três condições analisadas: alongamento estático, dinâmico e controle. Os resultados sugerem que o alongamento dinâmico é o mais indicado para ser realizado antes de atividades que exijam potência muscular, entretanto as intervenções propostas neste estudo não evidenciaram aumento na amplitude de movimento.

Basic principles regarding strength, flexibility, and stability exercises

Strength, flexibility, and stability are physiologic parameters associated with health-related physical fitness. Each of these domains affects health in general, the risk of injury, how an injury is treated, and performance in activities of daily living and sports. These domains are affected by individual phenotype, age, deconditioning, occupational activity, and formal exercise. Deficits or loss of strength, flexibility, and stability can be prevented or reduced with exercise programs. Normal muscle strength has been associated with general health benefits, increased life expectancy, psychological benefits, prevention of illness, and reduction of disability in older adults. Static flexibility programs have been shown to improve joint range of motion and tolerance to stretch but do not appear to reduce the risk of musculoskeletal injury and may impair muscle performance immediately after a static stretch. Dynamic flexibility, on the other hand, may enhance power and improve sports-specific performance. Stability training leads to improved balance and neuromuscular control, may prevent injury to the knee and ankle joints, and can be used for treatment of patients with low back pain.

Effect of acute static stretch on maximal muscle performance: a systematic review

INTRODUCTION

The benefits of preexercise muscle stretching have been recently questioned after reports of significant poststretch reductions in force and power production. However, methodological issues and equivocal findings have prevented a clear consensus being reached. As no detailed systematic review exists, the literature describing responses to acute static muscle stretch was comprehensively examined.

METHODS

MEDLINE, ScienceDirect, SPORTDiscus, and Zetoc were searched with recursive reference checking. Selection criteria included randomized or quasi-randomized controlled trials and intervention-based trials published in peer-reviewed scientific journals examining the effect of an acute static stretch intervention on maximal muscular performance.

RESULTS

Searches revealed 4559 possible articles; 106 met the inclusion criteria. Study design was often poor because 30% of studies failed to provide appropriate reliability statistics. Clear evidence exists indicating that short-duration acute static stretch (<30 s) has no detrimental effect (pooled estimate = -1.1%), with overwhelming evidence that stretch durations of 30-45 s also imparted no significant effect (pooled estimate = -1.9%). A sigmoidal dose-response effect was evident between stretch duration and both the likelihood and magnitude of significant decrements, with a significant reduction likely to occur with stretches ≥ 60 s. This strong evidence for a dose-response effect was independent of performance task, contraction mode, or muscle group. Studies have only examined changes in eccentric strength when the stretch durations were >60 s, with limited evidence for an effect on eccentric strength.

CONCLUSIONS

The detrimental effects of static stretch are mainly limited to longer durations (≥ 60 s), which may not be typically used during preexercise routines in clinical, healthy, or athletic populations. Shorter durations of stretch (<60 s) can be performed in a preexercise routine without compromising maximal muscle performance.