20-m Sprint Performance Research Articles

Faster Futsal Players Perceive Higher Training Loads and Present Greater Decreases in Sprinting Speed During the Preseason.

The aims of this study were to assess the speed-power characteristics of professional futsal players before and after a 9-week preseason and to explore possible relationships with internal training loads. Ten under-20 professional Brazilian futsal players performed unloaded (squat jump [SJ] and countermovement jump [CMJ]) and loaded (jump squat [JS]) jumps and a 20-m sprint test before and after the preseason. Weekly training loads as measured by session rating of perceived exertion (s-RPE) varied between 2,179 and 5,519 a.u. The magnitude-based inference statistics revealed that performance in the SJ, CMJ, and 20-m sprint very likely decreased (effect size [ES] = -0.64, -0.49, and -0.92, respectively), whereas mean propulsive power in the JS likely increased (ES = 0.42) in response to the preseason. The Pearson coefficient of correlation between velocity in the 20 m sprint test and s-RPE during the first 2 weeks of training was 0.66 (p ≤ 0.05) while no significant correlation was detected between total s-RPE (i.e., 9 weeks) and changes in the power-speed tests. The baseline 20-m sprint velocity was very largely and inversely (r = -0.90) correlated with the change in the 20-m sprint performance. In conclusion, futsal preseason training leads to impaired unloaded vertical jump and sprint test performance, with speed decreasing more in faster than slower players. In addition, because of the large correlation between baseline sprint ability and s-RPE, coaches are advised to assess sprinting performance at the beginning of the preseason to finely adjust the training stimuli to each athlete.

Improvement in 100-m Sprint Performance at an Altitude of 2250 m

A fair system of recognizing records in athletics should consider the influence of environmental conditions on performance. The aim of this study was to determine the effect of an altitude of 2250 m on the time for a 100-m sprint. Competition results from the 13 Olympic Games between 1964 and 2012 were corrected for the effects of wind and de-trended for the historical improvement in performance. The time advantage due to competing at an altitude of 2250 m was calculated from the difference between the mean race time at the 1968 Olympic Games in Mexico City and the mean race times at the low-altitude competition venues. The observed time advantage of Mexico City was 0.19 (±0.02) s for men and 0.21 (±0.05) s for women (±90% confidence interval). These results indicate that 100-m sprinters derive a substantial performance advantage when competing at a high-altitude venue and that an altitude of 1000 m provides an advantage equivalent to a 2 m/s assisting wind (0.10 s). Therefore, the altitude of the competition venue as well as the wind speed during the race should be considered when recognizing record performances.

The Effects of a 6-Week Strength Training on Critical Velocity, Anaerobic Running Distance, 30-M Sprint and Yo-Yo Intermittent Running Test Performances in Male Soccer Players.

The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. Methods: two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. Results: after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (p<0.001) with no significant changes in the SO group. 30-m sprint performance were slightly improved in the ST group with significantly decreased performance times identified in the SO group (p<0.001). Values for D' were slightly reduced in both groups (ST -44.5 m, 95% CI = -90.6 to 1.6; SO -42.6 m, 95% CI = -88.7 to 3.5). Conclusions: combining a 6-week moderate strength training with soccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer.

The effects of short-term detraining on exercise performance in soccer players

The aim of the present study was to determine whether 1 week of training cessation can affect exercise performance in well-trained soccer players. Upon the completion of a competitive season, 11 male soccer players went through 1-week training cessation. Performances in the 5-m (1.05±0.04 sec vs 1.02±0.03 sec, P=0.03) and 10-m (1.79±0.06 sec vs 1.74±0.06 sec, P=0.03) sprints were significantly increased after 1 week of detraining with a trend for an increase in the 20-m sprint performance (3.07±0.06 sec vs 3.02±0.07 sec, P=0.06). However, the repeated sprint performance (total sprint time [45.7±2.6 sec vs 48.0±2.6 sec, P=0.01] and fatigue index [5.8%±2.8% vs 7.8%±3.2%; P=0.04]) were reduced. In addition, no significant differences were observed for the 30 m (4.23±0.06 sec vs 4.24±0.09 sec, P=0.63), agility (right: 8.08±0.17 sec vs 8.03±0.37 sec, P=0.54; left: 8.05±0.21 sec vs 8.04±0.30 sec, P=0.84), coordination (13.98±1.21 sec vs 14.06±1.34 sec, P=0.75), Yo-Yo intermittent recovery level 2 (1,040.0±291.8 m vs 1,134.5±232.7 m, P=0.08), and knee extensors and flexors peak torques at all applied angular velocities (P<0.05) after detraining. These results indicate that short-term detraining for well-trained soccer players has a significant effect on the speed endurance performance. It is therefore important for the players and their coaches to plan a suitable training program to maintain exercise performance especially speed endurance during off-season.

Futbolcularda Baskın ve Baskın Olmayan Bacak İzokinetik Diz Kuvvetinin Karşılaştırması ve İzokinetik Kuvvet, Dikey Sıçrama ve Sürat Performansı Arasındaki İlişkiler

Objective: The purpose of this study was to compare isokinetic knee strength of the dominant and non-dominant legs in 17-20 year-old soccer players and to investigate the relationships among isokinetic knee strength, vertical jump, and 30-m sprint performance. Material and Methods: Thirtyix soccer players volunteered to participate in the study. The vertical jump height, 30-m sprint time, and the isokinetic strength of hamstring (HM) and quadriceps muscles (QM) at angular velocities of 60 and 240°?s -1 were determined using jump-meter, photocell, and an isokinetic dynamometer, respectively. Isokinetic knee strength between the dominant and non-dominant legs was compared using the paired t-test. Pearson correlation coefficient was used to analyze the relationships among the peak torque values and vertical jump and 30-m sprint performance. Results: H/Q ratio at 60°?s -1 and HM strength at 240°?s -1 were significantly greater in the dominant leg than that of the non-dominant leg (p<0.05). Vertical jump height correlated with 30-m sprint time (r=-0.40, p<0.05). QM strength correlated with 30-m sprint performance in the dominant and the non-dominant leg at 60°?s -1 (r=-0.36, p<0.05; r=-0.43, p<0.01, respectively) and at 240°?s -1 (r=-0.36, p<0.05; r=-0.34, p<0.05, respectively), and with vertical jumping at 60°?s -1 (r=0.37, r=0.38, p<0.05, respectively). Besides, dominant leg HM strength only showed a significant correlation with 30-m sprint performance at 240°?s -1 (r=-0.36, p<0.05). Conclusion: The results revealed that H/Q ratio at low velocity and HM strength at high velocity were higher in favor of dominant leg in 17-20 year-old players. The QM strength had a decisive role in vertical jump and 30-m sprint performances at low angular velocity, and in 30-m sprint performance at high angular velocity. In addition, only the HM strength of the dominant leg at high velocity was effective in 30-m sprint performance.

Relationship between Isometric Strength, Sprint, and Change of Direction Speed in Male Academy Cricketers

Objectives: The aim of this investigation was to determine the relationships between isometric strength, sprint, and change of direction speed (CODS) performance in academy cricketers. Design and Methods: Eighteen male academy cricketers (mean ± SD; age = 17.1 ± 0.7 years; height = 175.8 ± 6.1 cm; mass = 71.7 ± 11.3 kg) performed tests of bilateral and unilateral stance isometric mid-thigh pull (IMTP), sprint, and change of direction speed (CODS) across two separate testing sessions. Isometric mid-thigh pull testing involved trials with relative peak force (PF [N∙kgˉ¹]) determined for bilateral stance (IMTP PF), left leg (IMTP L PF), and right leg (IMTP R PF). Sprint and CODS performances was measured using 5-, 10-, and 20-m sprint performance, and traditional 505 (505) and modified 505 (505mod) tests. Relationships between variables (IMTP, sprint and CODS performances) were analysed using Pearson’s product – moment correlation. Results: Results suggest that IMTP R PF displayed the strongest relationships with sprint performance (r = − 0.49 to − 0.52). Times to complete 505 CODS were significantly correlated with bilateral and unilateral stance IMTP PF (r = − 0.47 to − 0.65), whereas modified 505mod CODS performance demonstrated no correlation to either bilateral or unilateral stance IMTP PF (r = − 0.31 to − 0.44). Conclusions: There are no significant relationships between bilateral and unilateral stance IMTP PF and 505mod CODS. Furthermore, there are no significant relationships between bilateral stance IMTP PF and sprint performance. However, this study identified bilateral and unilateral stance IMTP PF to relate to 505 CODS.

Soccer Player Characteristics in English Lower-League Development Programmes: The Relationships between Relative Age, Maturation, Anthropometry and Physical Fitness.

The relative age effect (RAE) and its relationships with maturation, anthropometry, and physical performance characteristics were examined across a representative sample of English youth soccer development programmes. Birth dates of 1,212 players, chronologically age-grouped (i.e., U9’s-U18’s), representing 17 professional clubs (i.e., playing in Leagues 1 & 2) were obtained and categorised into relative age quartiles from the start of the selection year (Q1 = Sep-Nov; Q2 = Dec-Feb; Q3 = Mar-May; Q4 = Jun-Aug). Players were measured for somatic maturation and performed a battery of physical tests to determine aerobic fitness (Multi-Stage Fitness Test [MSFT]), Maximal Vertical Jump (MVJ), sprint (10 & 20m), and agility (T-Test) performance capabilities. Odds ratio’s (OR) revealed Q1 players were 5.3 times (95% confidence intervals [CI]: 4.08–6.83) more likely to be selected than Q4’s, with a particularly strong RAE bias observed in U9 (OR: 5.56) and U13-U16 squads (OR: 5.45–6.13). Multivariate statistical models identified few between quartile differences in anthropometric and fitness characteristics, and confirmed chronological age-group and estimated age at peak height velocity (APHV) as covariates. Assessment of practical significance using magnitude-based inferences demonstrated body size advantages in relatively older players (Q1 vs. Q4) that were very-likely small (Effect Size [ES]: 0.53–0.57), and likely to very-likely moderate (ES: 0.62–0.72) in U12 and U14 squads, respectively. Relatively older U12-U14 players also demonstrated small advantages in 10m (ES: 0.31–0.45) and 20m sprint performance (ES: 0.36–0.46). The data identify a strong RAE bias at the entry-point to English soccer developmental programmes. RAE was also stronger circa-PHV, and relatively older players demonstrated anaerobic performance advantages during the pubescent period. Talent selectors should consider motor function and maturation status assessments to avoid premature and unwarranted drop-out of soccer players within youth development programmes.

Novel speed test for evaluation of badminton-specific movements.

In this study, we developed a novel badminton-specific speed test (BST). The test was designed to mimic match play. The test starts in the center of the court and consists of 5 maximal actions to sensors located in each of the 4 corners of the court. The 20 actions are performed in randomized order as dictated by computer screen shots displayed 1 second after completion of the previous action. We assessed day-to-day variation in elite players, and specificity of the test was evaluated by comparing 30-m sprint performance and time to complete the BST in 20 elite players, 21 skilled players, and 20 age-matched physical active subjects (non-badminton players). Sprint performance was similar across groups, whereas the elite players were significantly (p ≤ 0.05) faster in the BST (total test time: 32.3 ± 1.1 seconds; average: 1.6 seconds per action) than the skilled (34.1 ± 2.0 seconds) and non-badminton players (35.7 ± 1.7 seconds). Day-to-day coefficient of variation (CV) of the BST was 0.7% for the elite players, whereas CV for repeated tests on the same day was 1.7% for elite, 2.6% for skilled, and 2.5% for non-badminton players. On this basis, we suggest that the BST may be valuable for evaluation of short-term maximal movement speed in badminton players. Thus, the BST seems to be sport specific, as it may discriminate between groups (elite, less trained players, and non-badminton players) with similar sprinting performance, and the low test-retest variation may allow for using the BST to evaluate longitudinal changes, for example, training effects or seasonal variations.

Consecutive days of prolonged tennis match play: performance, physical, and perceptual responses in trained players.

To determine how consecutive days of prolonged tennis match play affect performance, physiological, and perceptual responses. Seven well-trained male tennis players completed 4-h tennis matches on 4 consecutive days. Pre- and postmatch measures involved tennis-specific (serve speed and accuracy), physical (20-m sprint, countermovement jump [CMJ], shoulder-rotation maximal voluntary contraction, isometric midthigh pull), perceptual (Training Distress Scale, soreness), and physiological (creatine kinase [CK]) responses. Activity profile was assessed by heart rate, 3D load (accumulated accelerations measured by triaxial accelerometers), and rating of perceived exertion (RPE). Statistical analysis compared within- and between-days values. Changes (± 90% confidence interval [CI]) ≥75% likely to exceed the smallest important effect size (0.2) were considered practically important. 3D load reduced on days 2 to 4 (mean effect size ± 90% CI -1.46 ± 0.40) and effective playing time reduced on days 3 to 4 (-0.37 ± 0.51) compared with day 1. RPE did not differ and total points played only declined on day 3 (-0.38 ± 1.02). Postmatch 20-m sprint (0.79 ± 0.77) and prematch CMJ (-0.43 ± 0.27) performance declined on days 2 to 4 compared with prematch day 1. Although serve velocity was maintained, compromised postmatch serve accuracy was evident compared with prematch day 1 (0.52 ± 0.58). CK increased each day, as did ratings of muscle soreness and fatigue. Players reduced external physical loads, through declines in movement, over 4 consecutive days of prolonged competitive tennis. This may be affected by tactical changes and pacing strategies. Alongside this, impairments in sprinting and jumping ability, perceptual and biochemical markers of muscle damage, and reduced mood states may be a function of neuromuscular and perceptual fatigue.

The effect of milk on the attenuation of exercise-induced muscle damage in males and females.

The consumption of 500ml milk following muscle damaging exercise can attenuate decreases in muscle functional capacity and increases in markers of muscle damage and soreness in males. There has been no similar research in female participants. Therefore, the aim of this study was to investigate the effects of milk consumption on exercise-induced muscle damage (EIMD) in males and females. Thirty-two team sport players (male n=16; female n=16) were randomly, but equally divided into four groups: male milk, male carbohydrate, female milk, and female carbohydrate. Immediately following muscle damaging exercise, participants consumed either 500ml of milk or 500ml of an energy-matched carbohydrate solution. Skeletal troponin I (sTnI), creatine kinase (CK), peak torque, counter movement jump height, 20m sprint performance and passive and active soreness were recorded prior to and 24, 48 and 72h post-EIMD. For females, milk had a likely/very likely beneficial effect on attenuating losses in peak torque at 60°/s from baseline to 24, 48 and 72h, and a likely beneficial effect in minimising decrements in sprint performance and soreness over 72h. Milk was unlikely to have a negative effect on serum markers of damage from baseline to 48 and 72h. For males, milk had an unclear effect on muscle function variables. Milk had a most likely/likely beneficial effect on limiting muscle soreness from baseline to 72h, and a possible beneficial effect on attenuating increases in CK. The effect on sTnI was unlikely to be negative from baseline-72h. Overall gender comparisons provided many unclear outcomes. However, female participants demonstrated smaller increases in sprint time, passive soreness, active soreness (non-dominant leg) and sTnI values. Consumption of 500ml of milk post-EIMD can limit decrements in muscle function in females, and limit increases in soreness and serum markers of muscle damage in females and males.

Relationship between isometric mid-thigh pull variables and sprint and change of direction performance in collegiate athletes

Objectives: The aim of this investigation was to assess the use of isometric strength testing as a determinant of sprint and change of direction performance in collegiate athletes. Design and Methods: Fourteen male collegiate athletes (mean ± SD; age = 21 ± 2.4 years; height =176 ± 9.0 cm; body mass = 72.8 ± 9.4 kg) participated in the study. Maximal strength was assessed via an isometric mid-thigh pull (IMTP). Isometric mid-thigh pull testing involved trials with peak force (IPF), maximum rate of force development (mRFD), impulse at 100 ms (IP 100) and 300 ms (IP 300) determined. Sprint and COD performance was measured using 5- and 20-m sprint performance, and a modified 505 test. Relationships between variables (IMTP, sprint and COD) were analysed using Pearson’s product – moment correlation. Results: Results suggest that IP 300 displayed the strongest relationships with 5- and 20-m sprint performance (r = −0.51 and −0.54, respectively). The results demonstrate maximum force production measures during IMTP correlate to sprint and COD ability in collegiate athletes. Conclusion: Isometric mid-thigh pull force-time measures are related to athletic performance (acceleration and sprinting), and thus are recommended for use in athlete monitoring and assessment.

The influence of playing surface on physiological and performance responses during and after soccer simulation

The aim of this study was to investigate the effect of playing surface on physiological and performance responses during and in the 48 h after simulated soccer match play. Blood lactate, single-sprint, repeated-sprint and agility of eight amateur soccer players were assessed throughout a 90-min soccer-simulation protocol (SSP) completed on natural turf (NT) and artificial turf. Counter-movement jump, multiple-rebound jump, sprint (10 m, 60 m), L-agility run (L-AR), creatine kinase (CK) and perception of muscle soreness (PMS) were measured before, immediately after, 24 h and 48 h after exercise. Analyses revealed significant changes in blood lactate and single-sprint performance (both P < 0.05) during the SSP but with no significant differences between surfaces. Conversely, repeated-sprint performance demonstrated an interaction effect, with reductions in performance evident on NT only (P < 0.05). Whilst L-AR and 10-m sprint performance remained unchanged, 60-m sprint and multiple-rebound jump performance were impaired, and PMS and CK were elevated immediately following the SSP (all P < 0.05) but with no surface effects. Although performance, CK and PMS were negatively affected to some degree in the 48 h after the SSP, there was no surface effect. For the artificial and natural surfaces used in the present study, physiological and performance responses to simulated soccer match play appear to be similar. Whilst a potential for small differences in performance response exists during activity, surface type does not affect the pattern of recovery following simulated match play.

Effect of High-Speed and Plyometric Training for 13-Year-Old Male Soccer Players on Acceleration and Agility Performance

Abstract Acceleration, sprint and agility performance are crucial in sports like soccer. There are few studies regarding the effect of training on youth soccer players in agility performance and in sprint distances shorter than 30 meter. Therefore, the aim of the recent study was to examine the effect of a high-intensity sprint and plyometric training program on 13-year-old male soccer players. A training group of 14 adolescent male soccer players, mean age (±SD) 13.5 years (±0.24) followed an eight week intervention program for one hour per week, and a group of 12 adolescent male soccer players of corresponding age, mean age 13.5 years (±0.23) served as control a group. Pre- and post-tests assessed 10-m linear sprint, 20-m linear sprint and agility performance. Results showed a significant improvement in agility performance, pre 8.23 s (±0.34) to post 7.69 s (± 0.34) (p&lt;0.01), and a significant improvement in 0-20m linear sprint, pre 3.54s (±0.17) to post 3.42s (±0.18) (p&lt;0.05). In 0-10m sprint the participants also showed an improvement, pre 2.02s (±0.11) to post 1.96s (± 0.11), however this was not significant. The correlation between 10-m sprint and agility was r = 0.53 (p&lt;0.01), and between 20-m linear sprint and agility performance, r = 0.67 (p&lt;0.01). The major finding in the study is the significant improvement in agility performance and in 0-20 m linear sprint in the intervention group. These findings suggest that organizing the training sessions with short-burst high-intensity sprint and plyometric exercises interspersed with adequate recovery time, may result in improvements in both agility and in linear sprint performance in adolescent male soccer players. Another finding is the correlation between linear sprint and agility performance, indicating a difference when compared to adults.

Association between Leg Power and Sprinting Technique with 20-m Sprint Performance in Elite Junior Australian Football Players

The main purpose of this study was to determine the association between leg power and sprint technique with 20-m sprint performance. Seventy-seven elite junior Australian Rules football players were assessed on a 20-m sprint test, a countermovement jump (CMJ) and a two bound test, and on a new method of quantifying sprint technique from simple video recordings. Technique assessment involved rating 14 points on a scale from 1–5. Players were median-split into faster and slower groups based on their 20-m times, and they were compared for differences in leg power and technique. The faster group was significantly better (p&lt;0.05) in the two-bound test (5.2%) and the technique score (8.2%), but not in the CMJ (p&gt;0.05). A multiple regression indicated that the two-bound test and technique accounted for 37.7% of the variance associated with the 20-m sprint time (p&lt;0.05). It was concluded that the technique assessment tool captured some important characteristics of 20-m sprint performance and could potentially be used to profile or monitor athletes. Further the two-bound test is a more relevant test for developing athletes because of its specificity to sprinting, compared to the CMJ.

9.58 and 10.49: nearing the citius end for 100 m?

Human upper performance limits in the 100-m sprint remain the subject of much debate. The aim of this commentary is to highlight the vulnerabilities of prognoses from historical trends by shedding light on the mechanical and physiological limitations associated with human sprint performance. Several conditions work against the athlete with increasing sprint velocity; air resistance and braking impulse in each stride increase while ground-contact time typically decreases with increasing running velocity. Moreover, muscle-force production declines with increasing speed of contraction. Individual stature (leg length) strongly limits stride length such that conditioning of senior sprinters with optimized technique mainly must be targeted to enhance stride frequency. More muscle mass means more power and thereby greater ground-reaction forces in sprinting. However, as the athlete gets heavier, the energy cost of accelerating that mass also increases. This probably explains why body-mass index among world-class sprinters shows low variability and averages 23.7±1.5 and 20.4±1.4 for male and female sprinters, respectively. Performance development of world-class athletes indicates that ~8% improvement from the age of 18 represents the current maximum trainability of sprint performance. However, drug abuse is a huge confounding factor associated with such analyses, and available evidence suggests that we are already very close to "the citius end" of 100-m sprint performance.

Analysis of Fatigue Development During Elite Male Handball Matches

This study aimed at describing the physiological demands and fatigue development during elite male handball matches. Our hypothesis was that players perform multiple high-intensity activities during periods of the game and develop temporary and end-match neuromuscular fatigue. Time-motion analyses and heart rate (HR) recordings were performed in 40 players during 12 competitive matches. Blood samples were collected, and sprint, jump, and intermittent exercise performance (Yo-Yo Intermittent Endurance level 2 test [YYIE2]) was assessed for 18 players at baseline conditions and after 2 competitive matches, and additional blood sampling and testing were performed for 12 of these players during a friendly match. The time spent with high-intensity running (4.4 ± 2.0 to 3.1 ± 1.7%), the frequency of demanding actions (61 ± 5 to 54 ± 6), and the time with HR above 80% HRmax (62 ± 21 to 41 ± 17%) were lowered from the first to the second half. Average blood lactate during the match was 3.6 ± 2.1 (1.3-8.6) mM. Plasma free fatty acids (FFA), glycerol, glucose, and uric acid increased (p ≤ 0.05) during the first half and plasma FFA and glycerol increased further (p ≤ 0.05) during the second half. After an intense period in the second half, sprint performance was decreased by 3.9 ± 4.9%. After the match, YYIE2 (33.4 ± 8.7%), vertical jump (7.4 ± 6.5%), and 20-m sprint performance (1.6 ± 2.6%) was lower (p ≤ 0.05) than at baseline. This study showed that the intensity is high in certain periods during elite male handball games and that physical performance is impaired both temporarily during and toward the end of games confirming our hypothesis. These findings enables physical trainers and coaches to plan and design proper game-specific training exercises aiming at delaying both temporary and end-game fatigue and strengthen the physiological rationale for the need for substitutions in various stages of match-play.

The contribution of vertical explosive strength to sprint performance in children

This study aimed to investigate the relationship between the explosive strength ratio, which is the quotient between maximum height achieved after counter-movement jump with arm and maximum height achieved after standing start jump, and the 30-m sprint performance. Eighty-four children performed a series of 30-m sprints, Counter-movement jump with arm (arm-CMJ) and Starting Long Jump (SLJ) (with both legs) in randomized block order during the same testing session. Pearson’s product moment correlation coefficients (r) were used to determine the relationship between the explosive strength ratio and sprint performance. The coefficients of determination (R 2) were used to examine the amount of explained variance between tests. Stepwise multiple regression analysis was used to estimate the best predictor model of sprint performance. The correlation coefficient between explosive strength Ratio: arm-CMJ/SLJ, 10, and 30-m sprint time was moderate (r = 0.40 and 0.48 respectively). However, correlation with flying time 10 < 30-m sprint time (r = 0.52) was large. The Ratio: arm-CMJ/SLJ was the best single predictor factor (p < 0.001) of the flying time 10 < 30-m sprint time, and explained 27 % of the variance. For improving sprint performance as well as maximal speed and flying time, coaches could ensure the explosive strength ratio as an index to calibrate sprint development program and also for enhancing sport speed in children. They will be able to use this finding to better test and monitor children’s athletes requiring different skills and to evaluate the effects of speed training in children.

Transference of traditional versus complex strength and power training to sprint performance.

The purpose of this study was to determine the effects of two different strength-power training models on sprint performance. Forty-eight soldiers of the Brazilian brigade of special operations with at least one year of army training experience were divided into a control group (CG: n = 15, age: 20.2 ± 0.7 years, body height: 1.74 ± 0.06 m, and body mass: 66.7 ± 9.8 kg), a traditional training group (TT: n = 18, age: 20.1 ± 0.7 years, body height: 1.71 ± 0.05 m, and body mass: 64.2 ± 4.7 kg), and a complex training group (CT: n = 15, age: 20.3 ± 0.8 years, body height: 1.71 ± 0.07 m; and body mass: 64.0 ± 8.8 kg). Maximum strength (25% and 26%), CMJ height (36% and 39%), mean power (30% and 35%) and mean propulsive power (22% and 28%) in the loaded jump squat exercise, and 20-m sprint speed (16% and 14%) increased significantly (p≤0.05) following the TT and CT, respectively. However, the transfer effect coefficients (TEC) of strength and power performances to 20-m sprint performance following the TT were greater than the CT throughout the 9-week training period. Our data suggest that TT is more effective than CT to improve sprint performance in moderately trained subjects.

Resisted Sprints Do Not Acutely Enhance Sprinting Performance

Sprinting speed is a vital component of successful performance in many sports. Long-term resisted sprint training has been shown to improve early acceleration performance, but the acute post-activation potentiation (PAP) effects of resisted sprinting on subsequent performance remain unclear. The purpose of this investigation was to examine the effects of resisted sprinting on sprinting and factors related to sprint performance. Twelve active males participated in a pretest involving ten 10-m sprints through dual-beam timing gates and 10-m Optojump Next System with full recovery. This provided baseline data on step rate, step length, ground contact time, and running speed over the first 6 steps of a maximum effort sprint. One week later, the participants performed three 10-m resisted sprints using a sled loaded to 25-30% body mass followed by a 10-m sprint at 1, 2, 4, 6, 8, and 10 minutes after the final resisted sprint. The data were analyzed using an adapted typical error analysis and repeated measures analysis of variance. The results using analysis of variance provided evidence of significant initial fatigue followed by the enhancement of mean step rate, contact time, reactive strength index, and running speed in 10-m sprints performed after the resisted sprinting (p > 0.05). By contrast, the typical error analysis showed that this enhancement was limited and unsystematic in nature with little clear evidence of fatigue followed by potentiation. The results using typical error data do not provide strong evidence of PAP in 10-m sprint performance after resisted sprinting.

Speed, force, and power values produced from nonmotorized treadmill test are related to sprinting performance.

The relationships between 30-m sprint time and performance on a nonmotorized treadmill (TM) test and a vertical jump test were determined in this investigation. Seventy-eight physically active men and women (22.9 ± 2.7 years; 73.0 ± 14.7 kg; 170.7 ± 10.4 cm) performed a 30-second maximal sprint on the curve nonmotorized TM after 1 familiarization trial. Pearson product-moment correlation coefficients produced significant (p ≤ 0.05) moderate to very strong relationships between 30-m sprint time and body mass (r = -0.37), %fat (r = 0.79), peak power (PP) (r = -0.59), relative PP (r = -0.42), time to peak velocity (r = -0.23) and TM sprint times at 10 m (r = 0.48), 20 m (r = 0.59), 30 m (r = 0.67), 40 m (r = 0.71), and 50 m (r = 0.75). Strong relationships between 30-m sprint time and peak (r = -0.479) and mean vertical jump power (r = -0.559) were also observed. Subsequently, stepwise regression was used to produce two 30-m sprint time prediction models from TM performance (TM1: body mass + TM data and TM2: body composition + TM data) in a validation group (n = 39), and then crossvalidated against another group (n = 39). As no significant differences were observed between these groups, data were combined (n = 72) and used to create the final prediction models (TM1: r = 0.75, standard error of the estimate (SEE) = 0.27 seconds; TM2: r = 0.84, SEE = 0.22 seconds). These final movement-specific models seem to be more accurate in predicting 30-m sprint time than derived peak (r = 0.23, SEE = 0.48 seconds) and mean vertical jump power (r = 0.31, SEE = 0.45 seconds) equations. Consequently, sprinting performance on the TM can significantly predict short-distance sprint time. It, therefore, may be used to obtain movement-specific measures of sprinting force, velocity, and power in a controlled environment from a single 30-second maximal sprinting test.