Changes In Sprint Times Research Articles

Limb-belt resisted sprint training improves physical fitness and ball-throw velocity in pubertal handball players.

The study assessed the effect of six weeks of biweekly upper and lower limbs' weighted-belt resisted sprint training (BRST) and weighted-vest resisted sprint training (VRST), or normal sprint training (NST) on muscle strength, speed, change of direction and handball-throwing velocity in young handball players. Twenty-seven pubertal male handball players aged 14.4 years were randomly assigned into BRST (n = 9), VRST (n = 8), and NST (n = 8) groups. Sprint ability (10-m and 30-m), squat jump (SJ), countermovement jump (CMJ), free-arm countermovement jump (CMJFA), standing long jump (SLJ), Five-jump test (FJT), change of direction and handball-throw velocity were assessed before and after a 6-week training in-season program. Within-group interactions showed that BRST improved all tests' performances (moderate-to-large). VRST improved sprint, SLJ, FJT and handball-throw velocity performances (small-to-large). NST improved only the change of direction performances (moderate). Between-groups comparison revealed that BRST improved all testing performances, except change of direction, compared with NST (large) and improved 30-m sprint, CMJFA, FJT and handball-throw velocity performance compared with VRST (moderate-to-large). In addition, VRST improved 30-m sprint, SJ and handball-throw velocity performances compared with NST (moderate-to-large). Throwing performance changes correlated with changes in sprint time and horizontal and vertical jump abilities (r = 0.40 to r = 0.69; p < 0.01). We conclude that while both resisted sprint training improved players' sprint, jumping and handball-throw performances, substantial improvements were recorded with the BRST compared to VRST and NST. Thus, BRST could be recommended to male U15 handball players as a valuable training method for developing physical fitness and skill performances.

Differential Repeated Sprinting Training in Youth Basketball Players: An Analysis of Effects According to Maturity Status.

The differential learning approach, which includes fluctuations that occur without movement repetitions and without corrections has received growing interest in the skill acquisition field. This study aimed to determine the effects of a 9-week training intervention involving differential repeated sprint training on a series of physical tests in youth basketball players. A total of 29 participants with different maturity statuses (pre-peak height velocity (PHV), n = 7; mid-PHV, n = 6; post-PHV, n = 16) completed 2 sessions per week of differential repeated sprint training for a period of 9 weeks. Sessions consisted of 2 × 10 repetitions sprints of 20-m whereby participants were instructed to perform various additional fluctuations for each repetition. Before and after the training intervention, participants completed jumping tests (countermovement jump (CMJ), single-leg CMJs, the modified 505 agility test, and straight sprinting tests (0–10 splits time), and maturity status was evaluated as well. Within-group analysis showed improvement in CMJ asymmetries and changes in direction asymmetries and 10-m sprint performance for the pre-, mid-, and post-PHV groups, respectively (p < 0.05), with large to very large effects. Analysis of covariance demonstrated that changes in sprint time in post-PHV players were greater than in the pre- and mid-PHV groups (p < 0.05), with moderate effect. Adding random fluctuations during repeated sprint training appear to be a suitable and feasible training strategy for maintaining and enhancing physical performance in youth basketball players, irrespective of maturity status. Furthermore, the present findings encourage practitioners to implement the present approach in youth athletes to improve their physical performance, but they should be aware that training response can vary according to maturity status.

Relationship between objective and subjective hydration measures on sprint performance among soccer players during actual matches in hot and humid environment.

Studies that investigate the effect of hydration on soccer performance in the heat are mostly carried out in a laboratory-controlled environment or simulated setting. Generally, on site, hydration is measured subjectively. Hence, the relationships between objective and subjective hydration measures during actual soccer matches in natural hot and humid environment with performance remain unclear. Forty-two soccer players (age: 27.34±3.62 years; BMI: 23.80±2.70 kg/m2; temperature: 30.8±1.92 °C; humidity: 82±1.4%) hydration status were assessed using urine specific gravity (USG) and bodyweight (BW) as the objective measures, meanwhile, thirst was measured subjectively using a thirst scale. For performance evaluation, 20 and 50 m sprint time were measured before and after match. The results showed a significant relationship between USG and sprint time (r=1.00, CI 0.98-0.99; P<0.05), and as expected, USG at post-match was significantly higher than pre-match (P<0.05) indicating dehydration. In line, changes (between post and pre-match) in BW also showed positive relationship with changes in sprint time (r=0.99, CI 0.98-0.99; P<0.05). Not to our expectation, the self-reported thirst level was not found to be correlated with USG and sprint time. Objective measures better reflect hydration status and predict sprint performance compared to subjective measure when playing in hot and humid environment. Players need to monitor their hydration status to maintain their sprint performances.

Sprinting, Strength, and Architectural Adaptations Following Hamstring Training in Australian Footballers.

The aim of this study was to determine the sprinting, strength, and architectural adaptations following a hip-dominant flywheel (FLY) or Nordic hamstring exercise (NHE) intervention in Australian footballers. Twenty-seven male athletes were randomized to FLY (n=13) or NHE (n=14) training across a 39-week period (inclusive of pre-season and in-season). Biceps femoris long head (BFlh) architecture was assessed throughout. Eccentric hamstring strength and 40m sprint times (with force-velocity profiling) were assessed at baseline, end of pre-season, and following the intervention. After the intervention, BFlh fascicle length was longer in both groups compared to baseline (FLY: 1.16cm, 95%CI: 0.66 to 1.66cm, d=1.99, p<0.001; NHE: 1.08cm, 95%CI: 95%CI 0.54 to 1.61cm, d=1.73, p<0.001). Both groups also increased their eccentric strength (FLY: mean change 82N, 95%CI 12 to 152N, d=1.34, p=0.026; NHE: mean change 97N, 95%CI 47 to 146N, d=1.77, p=0.001). After pre-season, the NHE group improved their 5m sprint time by 3.5% (±1.2%) and were 3.7% (±1.4%) and 2.0% (±0.5%) faster than the FLY group across 5m and 10m, respectively. At the end of pre-season, the FLY group improved maximal velocity by 3.4% (±1.4%) and improved horizontal force production by 9.7% in-season (±2.2%). Both a FLY and NHE intervention increase BFlh fascicle length and eccentric strength in Australian Footballers. An NHE intervention led to enhanced acceleration capacity. A FLY intervention was suggested to improve maximal sprint velocity and horizontal force production, without changes in sprint times. These findings have implications for hamstring injury prevention but also programs aimed at improving sprint performance.

Strength and Sprint Time Changes in Response to Repeated Shuttles Between the Wickets During Batting in Cricket.

Christie CJ, Sheppard B, Goble D, Pote L, and Noakes TD. Strength and sprint time changes in response to repeated shuttles between the wickets during batting in cricket. J Strength Cond Res 33(11): 3056-3064, 2019-No studies have investigated the impact of repeated sprints between the wickets on lower-limb strength and sprint performance. Therefore, the purpose of this study was to assess changes in knee extensor (EXT) and flexor (FLEX) strength after repeated sprints between the wickets and to relate these to changes in sprint times. Twenty batters completed 2 conditions: one was high-volume running (HVR-twelve sprints per over) and the other, moderate-volume running (MVR-6 sprints per over) between the wickets (42 deliveries in both). Peak isokinetic torque was measured before and after each condition and sprint times were recorded. Eccentric and concentric peak torque decreased significantly (p < 0.05) at 1.05 rad·s for knee EXT in both conditions. There was an 18% (HVR) and 10% (MVR) decline in concentric and eccentric knee EXT peak torque. Peak FLEX torques were significantly (p < 0.05) reduced after HVR (16.7%) but not after the MVR condition (8%). There were similar declines in eccentric FLEX peak torque. Sprint times increased significantly (p < 0.05) during the HVR condition but not in the MVR condition; sprint times in the HVR condition were compromised as early as the third over. We conclude that a high volume of runs significantly reduces muscle function in the lower limbs, partly explaining the impairment in sprint performance. However, because batters slowed as early as the third over in the HVR condition, there may be some form of strategy used in anticipation of a higher overall workload. More middle wicket practices, focusing on repeat shuttle sprints while batting, should be included in the coaching program.

Heavy Barbell Hip Thrusts Do Not Effect Sprint Performance: An 8-Week Randomized Controlled Study.

Jarvis, P, Cassone, N, Turner, A, Chavda, S, Edwards, M, and Bishop, C. Heavy barbell hip thrusts do not effect sprint performance: an 8-week randomized controlled study. J Strength Cond Res 33(7S): S78-S84, 2019-The purpose of this study was to examine the effects of an 8-week barbell hip thrust strength training program on sprint performance. Twenty-one collegiate athletes (15 males and 6 females) were randomly assigned to either an intervention (n = 11, age 27.36 ± 3.17 years, height 169.55 ± 10.38 cm, mass 72.7 ± 18 kg) or control group (n = 10, age 27.2 ± 3.36 years, height 176.2 ± 7.94 cm, mass 76.39 ± 11.47 kg). One repetition maximum hip thrust, 40-m sprint time, and individual 10-m split timings: 0-10, 10-20, 20-30, and 30-40 m were the measured variables; these recorded at both the baseline and posttesting time points. After the 8-week hip thrust strength training intervention, significantly greater 1 repetition maximum (1RM) hip thrust scores for the training group were observed (p < 0.001, d = 0.77 [mean difference 44.09 kg]); however, this failed to translate into changes in sprint time for any of the measured distances (all sprint performance measures: p > 0.05, r = 0.05-0.37). No significant differences were seen for the control group for 1RM hip thrust (p = 0.106, d = 0.24 [mean difference 9.4 kg]) or sprint time (all sprint performance measures: p > 0.05, r = 0.13-0.47). These findings suggest that increasing maximum hip thrust strength through the use of the barbell hip thrust does not seem to transfer into improvements in sprint performance in collegiate level athletes.

The effects of fatigue on the running profile of elite team sport athletes. A systematic review and meta-analysis.

With the underlying mechanisms of fatigue shown to be task-specific, gaining an understanding of changes within the running profile due to fatigue may provide a greater task-specific method for monitoring neuromuscular fatigue (NMF) in elite team sport athletes. This review aimed to identify, review and summarize the literature to understand the effects of fatigue on the running profile of elite team sport athletes. MEDLINE, SPORTDiscus, EMBASE and CINAHL were searched. To manage heterogeneity in athlete characteristics and sport demands, studies were limited to elite male field/court team sports, in which changes in running, gait or stride characteristics were assessed. Thirteen studies were included in the analysis with changes in sprint time, kinematic variables; contact time, center of mass vertical displacement and vertical stiffness, GPS accelerometer vector variables; z and y, and mechanical parameters; velocity and V0, all shown to be sensitive measures of fatigue. Due to having at least three sets of data points, meta-analysis was run for sprint time, with results showing a significant increase immediately postexercise (effect size [ES]±95% confidence interval [CI]; 1.67±1.61, P=0.04), but no change 24 hours postexercise (ES±95% CI; 0.93±3.21, P=0.57). The findings indicate that fatigue has a negative impact on the running profile in elite team sport athletes, offering an alternative task-specific measure of monitoring NMF in this population. However, due to large discrepancies in protocols, future research is required to allow greater uniformity in variables and methods.

Effects of Resistance Training and Combined Training Program on Repeated Sprint Ability in Futsal Players.

The purpose of this study was to compare the effects of 6 weeks resistance training (RT) with combined RT and loaded change of direction (CD) exercise on muscle strength and repeated sprint ability (RSA) in futsal players. Thirty-four players (age: 23.7±4.1 years; height: 1.77±0.06 m; body mass: 74.1±8.2 kg) were randomly assigned into three groups: full squat group (SG, n=12), combined full squat and CD group (S+CDG, n=12), and control group (CG, n=10). The RT for SG consisted of full squat with low-load (~45-60% 1RM) and low-volume (2-3 sets and 4-6 repetitions), whereas the S+CDG performed the same RT program combined with loaded CD (2-5 sets of 10 s). Estimated one-repetition maximum (1RMest) and variables derived from RSA test including mean sprint time (RSAmean), best sprint time (RSAbest), percent sprint decrement (Sdec), mean ground contact time (GCTmean) and mean step length (SL) were selected as testing variables. Changes in sprint time and GCT in each sprint were also analysed. Both experimental groups showed significant (P<0.05-0.001) improvements for 1RMest, RSAbest and first and second sprint time. In addition, S+CDG achieved significant (P<0.05-0.001) improvements in RSAmean, sprint time (from fifth to ninth sprint) and GCT (from third to eighth sprint). These results indicate that only 6 weeks of low-load and low-volume RT combined with CD in addition to routine futsal training is enough to improve RSA and strength performance simultaneously in futsal players.

A PILOT ANALYSIS: CAN THE BULGARIAN SPLIT-SQUAT POTENTIATE SPRINT ACCELERATION IN STRENGTH-TRAINED MEN?

This study determined whether a five repetition-maximum Bulgarian split-squat (5RM BSS) could potentiate a 0-5, 0-10, and 0-20 m (meter) sprint performance. Seven men were assessed in the 5RM BSS (a linear position transducer measured peak power [PP] and force [PF] for each leg), and completed two post activation potentiation (PAP) sessions. One session involved a control condition (CC) of 4 minutes (min) rest; the other the 5RM BSS. Participants were assessed in baseline sprints, and sprints of 15 seconds, 2, 4, 8, 12, and 16 min post-PAP intervention. A repeated measures ANOVA (p &lt; 0.05) calculated significant changes in sprint times. The best potentiated time for each interval was also compared to the baseline. Spearman’s correlations (r; p &lt; 0.05) calculated relationships between absolute and relative strength, PP and PF, with percent potentiation in sprint times. The BSS did not potentiate speed at any time, although there was great individual variation. The best 0-5 m time was significantly different from the baseline (p = 0.022), with no differences between PAP conditions. Significant correlations were found between strength and sprint potentiation at 16 min for the 0-5 m interval, and at 8 min and the best times for the 0-20 m interval (r = -0.786 to -0.893). There were correlations between PP and PF for each leg with sprint potentiation from 2-12 min across all intervals (r = -0.786 to -0.964). Stronger individuals who generate greater PP and PF in a 5RM BSS will be more likely to potentiate 20-m sprint performance.

Influence of shoe sole bending stiffness on sprinting performance.

This study investigated the influence of shoe sole bending stiffness on sprint performance, in relation to anthropometric and strength-power capability characteristics of sprinters. Seventeen male athletes performed three maximal effort 60-m sprints using spiked-shoes with different bending stiffness sole. Sprint times during 60-m sprint, anthropometry and strength-power capabilities represented by maximum toe-flexor test and rebound continuous ankle jump (AJ) of athletes were measured. The sprint times did not differ when shoe sole bending stiffness was altered by carbon fiber plates (CFPs) of 13.4 and 37.1 N/mm. The optimal bending stiffness for the fastest sprint was not associated with any anthropometric and strength-power variables. As results of stepwise-multiple-regression analyses, however, the left maximum toe-flexor strength (TFS) and contact time and jump height of rebound continuous AJ for a 0-30-m section with CFP of 13.4 N/mm, body mass for a 0-30-m section with CFP of 37.1 N/mm, and the left maximum TFS for a 30-60-m section with CFP of 37.1 N/mm were selected as predictors of changes in sprint times with stiffer sole shoes. These results indicate that, although sole bending stiffness of spiked-shoe may not affect the sprinting performance on average, changes in sprint time by the use of stiffer sole spiked-shoe for individuals will be predicted by toe-flexor strength, rebound continuous AJ performance, and body mass. The findings obtained here can be useful information for sprinters and coaches to choose the spiked shoe with an appropriate bending stiffness of sole for individuals.

Limited Post-activation Potentiation Effects Provided by the Walking Lunge on Sprint Acceleration: A Preliminary Analysis

Background:Bilateral strength exercises may not provide a movement-specific stimulus to achieve post-activation potentiation (PAP) for sprinting. The walking lunge (WL) could provide this, due to its unilateral action similar to the running gait.Objective:To determine whether the WL potentiated 20-m sprint performance.Method:Nine strength-trained individuals (six men, three women) completed a five-repetition maximum (5RM) WL in one session, and two PAP sessions (control condition [CC] of 4 minutes rest and 5RM WL). Subjects were assessed in baseline 20-m (0-5, 0-10, 0-20 m intervals) sprints, and sprints ~15 s, 2, 4, 8, 12, and 16 min post-PAP intervention. Repeated measures ANOVA calculated significant changes in sprint times. The best potentiated time for each interval was compared to the baseline to individualize subject recovery times. Effect sizes (d) were derived for magnitude-based inference comparisons between the baseline and all sprints. Sprint potentiation and strength measured by the WL were also correlated (p&lt; 0.05).Results:There were no significant interactions between the PAP conditions and any time point (p= 0.346-0.898). Magnitude based-inference showed a trivial 0.72% decrease in 0-5 m time 4 min after the 5RM WL. There was a moderate potentiation effect following the 5RM WL for the 0-5 m interval best time (d= 0.34). The correlation data did not suggest that greater strength in the WL aided sprint potentiation.Conclusion:The 5RM WL did not significantly potentiate sprint speed. The WL requires stability and control which could limit the applied load and resulting potentiation.

Postactivation Potentation Effects From Accommodating Resistance Combined With Heavy Back Squats on Short Sprint Performance.

Applying accommodating resistance combined with isoinertial resistance has been demonstrated to be effective in improving neuromuscular attributes important for sport performance. The main purpose of this study was to determine whether short sprints can be acutely enhanced after several sets of back squats with or without accommodating resistance. Twenty recreationally resistance-trained males (age: 23.3 ± 4.4 years; height: 178.9 ± 6.5 cm; weight: 88.3 ± 10.8 kg) performed pre-post testing on 9.1-m sprint time. Three different interventions were implemented in randomized order between pre-post 9.1-m sprints. On 3 separate days, subjects either sat for 5 minutes (CTRL), performed 5 sets of 3 repetitions at 85% of their 1 repetition maximum (1RM) with isoinertial load (STND), or performed 5 sets of 3 repetitions at 85% of their 1RM, with 30% of the total resistance coming from elastic band tension (BAND) between pre-post 9.1-m sprint testing. Posttesting for 9.1-m sprint time occurred immediately after the last set of squats (Post-Immediate) and on every minute for 4 minutes after the last set of squats (Post-1min, Post-2min, Post-3min, and Post-4min). Repeated-measures analysis of variance statistical analyses revealed no significant changes in sprint time across posttesting times during the CTRL and STND condition. During the BAND condition, sprint time significantly decreased from Post-Immediate to Post-4min (p = 0.002). The uniqueness of accommodating resistance could create an optimal postactivation potentiation effect to increase neuromuscular performance. Coaches and athletes can implement heavy accommodating resistance exercises to their warm-up when improving acute sprint time is desired.

Effect of cold water immersion on 100-m sprint performance in well-trained swimmers

The aim of the present study was to examine the effect of cold water immersion (CWI) on sprint swimming performance in simulated competition conditions. Ten well-trained swimmers (5 males, 5 females; 19.0 +/- 3.9 years) performed two 100-m swimming sprints (S1 and S2) interspersed with a 30-min passive recovery period, during which athletes were randomly assigned to 5 min of CWI (14 degrees C) or an out-of-water control condition (CON 28 degrees C). During tests, sprint times, heart rate (HR), pre- and post-race parasympathetic activity via HR variability (natural logarithm of the square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals; Ln rMSSD) and blood lactate accumulation ([La](ac)) and clearance ([La](cle)) were recorded. Rates of perceived recovery (RPR) and exertion (RPE) were evaluated before and after each sprint. CWI was associated with a 'likely' decrease in swimming performance [1.8% (90% CI 0.2, 3.5)], as well as 'likely' lower peak HR [-1.9% (-3.6, -0.2)]. CWI was also associated with a 'likely' smaller decrease in Ln rMSSD after the first sprint [-16.7% (-30.9, -4.1)]. RPR was 'likely' better [+27.2% (-3.7, 68.0)] following CWI. 'unclear' effects were observed for [La](ac) [+24.7% (-13.4, 79.5)], [La](cle) [-7.6% (-24.2, 12.7)] or RPE [+2.0% (-12.3, 18.5)]. Following CWI, changes in sprint times were 'largely' correlated with changes in peak HR (r = 0.80). Despite a subjective perception of improved recovery following CWI, this recovery intervention resulted in slower swimming times in well-trained athletes swimming in simulated competition conditions.

Effects of a Plyometrics Intervention Program on Sprint Performance

To determine the effects of a sprint-specific plyometrics program on sprint performance, an 8-week training study consisting of 15 training sessions was conducted. Twenty-six male subjects completed the training. A plyometrics group (N = 10) performed sprint-specific plyometric exercises, while a sprint group (N = 7) performed sprints. A control group (N = 9) was included. Subjects performed sprints over 10-and 40-m distances before (Pre) and after (Post) training. For the plyometrics group, significant decreases in times occurred over the 0–10-m (Pre 1.96 ± 0.10 seconds, Post 1.91 ± 0.08 seconds, p = 0.001) and 0–40-m (Pre = 5.63 ± 0.18 seconds, Post = 5.53 ± 0.20 seconds, p = 0.001) distances, but the improvements in the sprint group were not significant over either the 0–10-m (Pre 1.95 ± 0.06 seconds, Post 1.93 ± 0.05 seconds) or 0–40-m distance (Pre 5.62 ± 0.14 seconds, Post 5.55 ± 0.10 seconds). The magnitude of the improvements in the plyometrics group was, however, not significantly different from the sprint group. The control group showed no changes in sprint times. There were no significant changes in stride length or frequency, but ground contact time decreased at 37 m by 4.4% in the plyometrics group only. It is concluded that a sprint-specific plyometrics program can improve 40-m sprint performance to the same extent as standard sprint training, possibly by shortening ground contact time.