The relationship between running speed and measures of vertical jump in professional basketball players: a field-test approach

The purpose of this study was to examine the relationship between vertical jump measures and sprint speed over 10, 20, and 40 m in professional basketball players. Thirty-three professional basketball players aged (±SD) (27.4 ± 3.3 years), body mass (89.8 ± 11.1 kg), and stature (192 ± 8.2 cm) volunteered to participate in this study. All participants were tested on squat jump, countermovement jump, and 40-m running speed. The results show that all jump measures in absolute terms were correlated significantly to running performance over 10-, 20-, and 40-m sprint times. None of the jumping performance peak powers and reactive strength were found to have a correlation to running speed times in absolute term. Furthermore, all jump height measures relative to body mass except reactive strength had a marked and significant relationship with all sprint performance times. The results of this study indicate that while there is a strong and marked relationship between 10-, 20-, and 40-m sprint, there is also a considerable variation within the factors that contribute to performance over these distances. This may indicate that, separate training strategies could be implemented to improve running speed over these distances.     

Repeated sprint training improves intermittent peak running speed in team-sport athletes

The aim of this study was to compare the effect of 2 repeated sprint training interventions on an intermittent peak running speed (IPRS) test designed for Australian Rules football. The test required participants to perform 10 × 10-m maximal efforts on an 80-m course every 25 seconds, for each of which the mean peak speed (kilometers per hour) was recorded to determine IPRS. The training interventions were performed twice weekly for 4 weeks immediately before regular football training. In the constant volume intervention (CVol), sprint repetition number remained at 10 (n = 9), and in the linear increase in volume (LIVol) intervention, repetition number increased linearly each week by 2 repetitions (n = 12). Intermittent peak running speed, 300-m shuttle test performance, and peak running speed were assessed before and upon completion of training. All measures were compared to a control group (CON; n = 8) in which players completed regular football training exclusively. Intermittent peak running speed performance in CVol and LIVol improved significantly (p < 0.01) by 5.2 and 3.8%, respectively, with no change in IPRS for CON. There were no differences in IPRS changes between CVol and LIVol. Additionally, peak running speed improved significantly (p < 0.01) by 5.1% for CVol, whereas 300-m shuttle performance improved significantly (p < 0.01) by 2.6% for LIVol only. Intermittent peak running speed, 300-m shuttle performance and peak running speed were improved after 4 weeks of training; however, progressively increasing sprint repetition number had no greater advantage on IPRS adaptation. Additionally, exclusive regular football training over a 4-week period is unlikely to improve IPRS, peak running speed, or 300-m shuttle performance.     

Influence of short vs. long repetition sprint training on selected fitness components in young soccer players

The aim of this study was to compare the effect of short-sprint repetition and long-sprint repetition training (SST, LST), matched for total distance, on selected fitness components in young soccer players. Thirty young (14-15 years) soccer players were randomly assigned to either the short-sprint training group or long-sprint training group and completed 2 similar sets of fitness tests before and after 7 weeks of training. The 2 training programs consisted of SST (4-6 sets of 4 × 50-m all-out sprint) and LST (4-6 sets of 200-m run at 85% of maximum speed), each performed 3 times a week. Before training, there were no baseline between-group differences in predicted VO2max, standing long jump, 30-m sprint time, 4 × 10-m shuttle running time, and 250-m running time. Both training programs led to a significant improvement in VO2max (predicted from the 20-m shuttle run, p < 0.01), with no between-group difference (p = 0.14). Both training programs also led to a significant improvement in the anaerobic fitness variables of 30-m sprint time (p < 0.01), 4 × 10-m shuttle running time (p < 0.01), and 250-m running time (p < 0.01), with no between-group differences. Neither of the training programs had a significant effect on standing long jump (p = 0.21). The study showed that long, near-maximal sprints, and short, all-out sprint training, matched for total distance, are equally effective in enhancing both the aerobic and anaerobic fitness of young soccer players. Therefore, to maintain a player's training interest and enthusiasm, coaches may alternate between these methods during the busy soccer season.     

The effects of a constant sprint-to-rest ratio and recovery mode on repeated sprint performance

It is unclear if a constant sprint-to-rest ratio allows full performance recovery between repeated sprints over different distances. This is important for the development of sprint-training programs. Additionally, there is conflicting evidence on whether active recovery enhances sprint performance. Three repeated sprint protocols were used (22 × 15, 13 × 30, and 8 × 50 m), with each having an active and passive recovery. Each trial was conducted with an initial sprint-to-rest ratio of 1:10. Repeated sprints were analyzed by comparing the first sprint to the last sprint. For the 15-m trials, there were no significant main effects for recovery or time and no significant interaction. For the 30-m trials, there was no main effect for recovery, but a main effect for time (F[1,10] = 15.995, p = 0.003; mean difference = 0.20 seconds, 95% confidence interval [CI] = 0.09-0.31 seconds, d = 1.4 [large effect]). There was no interaction of recovery and time in the 30-m trials. For the 50-m trials, there was no main effect for recovery, but a main effect for time (F[1,10] = 34.225, p = 0.0002; mean difference = 0.39 seconds, 95% CI = 0.24-0.55 seconds, d = 1.3 [large effect]). There was no interaction of recovery and time in the 50-m trials. The results demonstrate that a 1:10 sprint-to-rest ratio allows full performance recovery between 15-m sprints, but not between sprints of 30 or 50 m, and that recovery mode did not influence repeated sprint performance.     

Relationships between repeated sprint testing, speed, and endurance

Repeated sprint testing is gaining popularity in team sports, but the methods of data analysis and relationships to speed and endurance qualities are not well described. We compared three different methods for analyzing repeated sprint test results, and we quantified relationships between repeated sprints, short sprints, and endurance test scores. Well-trained male junior Australian Football players (n = 60, age 18.1 +/- 0.4 years, height 1.88 +/- 0.07 m, mass 82.0 +/- 8.1 kg; mean +/- SD) completed a 6 x 30-m repeated sprint running test on a 20-second cycle, a 20-m sprint test (short sprint), and the 20-m multistage shuttle run for endurance. Repeated sprint results were evaluated in three ways: total time for all six sprints (TOTAL), percent change from predicted times (PRED) from the fastest 30-m sprint time, and percent change from first to last sprint (CHANGE). We observed a very large decrement (CHANGE 6.3 +/- 0.7%, mean +/- 90% confidence limits) in 30-m performance from the first to last sprint (4.16 +/- 0.10 to 4.42 +/- 0.11 seconds, mean +/- SD). Results from TOTAL were highly correlated with 20-m sprint and 20-m multistage shuttle run tests. Performance decrements calculated by PRED were highly correlated with TOTAL (r = 0.91), but neither method was directly comparable with CHANGE (r = -0.23 and r = 0.12 respectively). TOTAL was moderately correlated with fastest 20-m sprint time (r = 0.66) but not the 20-m multistage shuttle run (r = -0.20). Evaluation of repeated sprint testing is sensitive to the method of data analysis employed. The total sprint time and indices of the relative decrement in performance are not directly interchangeable. Repeated sprint ability seems more related to short sprint qualities than endurance fitness.     

The effect of 40-m repeated sprint training on maximum sprinting speed, repeated sprint speed endurance, vertical jump, and aerobic capacity in young elite male soccer players

The purpose of this study was to examine the effect of 10 weeks' 40-m repeated sprint training program that does not involve strength training on sprinting speed and repeated sprint speed on young elite soccer players. Twenty young well-trained elite male soccer players of age (±SD) 16.4 (±0.9) years, body mass 67.2 (±9.1) kg, and stature 176.3 (±7.4) cm volunteered to participate in this study. All participants were tested on 40-m running speed, 10 × 40-m repeated sprint speed, 20-m acceleration speed, 20-m top speed, countermovement jump (CMJ), and aerobic endurance (beep test). Participants were divided into training group (TG) (n = 10) and control group (CG) (n = 10). The study was conducted in the precompetition phase of the training program for the participants and ended 13 weeks before the start of the season; the duration of the precompetition period was 26 weeks. The TG followed a Periodized repeated sprint training program once a week. The training program consisted of running 40 m with different intensities and duration from week to week. Within-group results indicate that TG had a statistically marked improvement in their performance from pre to posttest in 40-m maximum sprint (-0.06 seconds), 10 × 40-m repeated sprint speed (-0.12 seconds), 20- to 40-m top speed (-0.05 seconds), and CMJ (2.7 cm). The CG showed only a statistically notable improvement from pre to posttest in 10 × 40-m repeated sprint speed (-0.06 seconds). Between-group differences showed a statistically marked improvement for the TG over the CG in 10 × 40-m repeated sprint speed (-0.07 seconds) and 20- to 40-m top speed (-0.05 seconds), but the effect of the improvement was moderate. The results further indicate that a weekly training with repeated sprint gave a moderate but not statistically marked improvement in 40-m sprinting, CMJ, and beep test. The results of this study indicate that the repeated sprint program had a positive effect on several of the parameters tested. However, because the sample size in this study is 20 participants, the results are valid only for those who took part in this study. Therefore, we advice to use repeated sprint training similar to the one in this study only in periods where the players have no speed training included in their program. Furthermore, the participants in this study should probably trained strength, however, benefits were observed even without strength training is most likely to be caused by the training specificity.     

Strength and power predictors of sports speed

For many sporting activities, initial speed rather than maximal speed would be considered of greater importance to successful performance. The purpose of this study was to identify the relationship between strength and power and measures of first-step quickness (5-m time), acceleration (10-m time), and maximal speed (30-m time). The maximal strength (3 repetition maximum [3RM]), power (30-kg jump squat, countermovement, and drop jumps), isokinetic strength measures (hamstring and quadriceps peak torques and ratios at 60 degrees .s(-1) and 300 degrees .s(-1)) and 5-m, 10-m, and 30-m sprint times of 26 part-time and full-time professional rugby league players (age 23.2 +/- 3.3 years) were measured. To examine the importance of the strength and power measures on sprint performance, a correlational approach and a comparison between means of the fastest and slowest players was used. The correlations between the 3RM, drop jump, isokinetic strength measures, and the 3 measures of sport speed were nonsignificant. Correlations between the jump squat (height and relative power output) and countermovement jump height and the 3 speed measures were significant (r = -0.43 to -0.66, p < 0.05). The squat and countermovement jump heights as well as squat jump relative power output were the only variables found to be significantly greater in the fast players. It was suggested that improving the power to weight ratio as well as plyometric training involving countermovement and loaded jump-squat training may be more effective for enhancing sport speed in elite players.     

Familiarization and reliability of multiple sprint running performance indices

The aims of this study were to evaluate the time-course of the familiarization process associated with a test of multiple sprint running performance and to determine the reliability of various performance indices once familiarization had been established. Eleven physically active men (mean age: 21 +/- 2 years) completed 4 multiple sprint running trials (12 x 30 m; repeated at 35-s intervals) with 7 days between trials. All testing was conducted indoors, and times were recorded by twin-beam photocells. Results revealed no apparent learning effects as evidenced by no significant (p > 0.05) between-trial differences in measures of fastest or mean 30-m sprint time. Within-subject test-retest reliability determined over 4 trials by coefficient of variation (CV) and intraclass correlation coefficient (ICC) showed excellent reliability for measures of fastest and mean sprint times (CV range: 1.34-2.24%; ICC range: 0.79-0.94). Pre- and posttrial blood lactate concentrations showed good reliability when judged in context with typical values (CV range: 12.08-18.21%; ICC range: 0.72-0.78). In contrast, and in line with previous research, fatigue data showed much greater variability (CV: 26.43%; ICC: 0.66). The results of this study suggest that high degrees of test-retest reliability can be obtained in many multiple sprint running indices without the need for prior familiarization.     

Effect of creatine supplementation on intermittent sprint running performance in highly trained athletes

This study examined the impact of short-term (7-day), high-dose (0.35 g.kg(-1).d(-1)) oral creatine monohydrate supplementation (CrS) on single sprint running performance (40 m, <6 seconds) and on intermittent sprint performance in highly trained sprinters. Nine subjects completed the double-blind cross-over design with 2 supplementation periods (placebo and creatine) and a 7-week wash-out period. A test protocol consisting of 40-m sprint runs was performed, and running velocity was continuously recorded over the total distance. The maximal sprint performance, the relative degree of fatigue at the end of intermittent sprint exercise (6 x 40 m, 30-second rest interval), as well as the degree of recovery (120-second passive rest) remained unchanged following CrS. There were no significant changes related to CrS in absolute running velocity at any distance between start and finish (40 m). It was concluded that no ergogenic effect on single or repeated 40-m sprint times with varying rest periods was observed in highly trained athletes.     

The acute effects of heavy back and front squats on speed during forty-meter sprint trials

The purpose of the present study was to investigate the effects of performing heavy back squats (HBS) and heavy front squats (HFS) on the average speed during each 10-m interval of 40-m sprint trials. In a randomized, cross-over design, 10 strength-trained men performed a HBS, HFS, or control treatment before performing three 40-m sprint trials separated by 3 minutes. The HBS and HFS treatments consisted of performing parallel back or front squats with 30%, 50%, and 70% of the subject's 1 repetition maximum after 5 minutes of cycling. The control treatment consisted of cycling for 5 minutes. The sprint trials were performed 4 minutes after completing the HBS, HFS, or control treatments. Significant increases in speed were found during the 10- to 20-m interval for the HBS compared with the control treatment (mean difference, 0.12 m x s(-1); 95% likely range, 0.05-0.18 m x s(-1); P = 0.001). During the 30- to 40-m interval, HBS produced significantly greater speeds compared with the HFS treatment (mean difference, 0.24 m x s(-1); 95% likely range, 0.02-0.45 m x s(-1); P = 0.034) and the control treatment (mean difference, 0.18 m x s(-1); 95% likely range, 0.03-0.32 m x s(-1); P = 0.021). The differing effects of the treatments may reflect different levels of muscular activation or different mechanical aspects of the squat exercises. Similarly, the multidimensional nature of sprint running means that other specific exercises may confer improvements in sprinting performance during other intervals. It is suggested that coaches could incorporate HBS into the warm-up procedure of athletes to improve sprinting performance.     

Stepping back to improve sprint performance: a kinetic analysis of the first step forwards

Using a step backward to initiate forward movement can increase force and power at push-off and improve sprint performance over short distances. However, it is not clear whether the benefit provided by this paradoxical step influences the mechanics of the first step forwards. Twenty-seven men of an athletic background performed maximal effort 5-m sprints from a standing start and employed a step forwards (parallel and split stance) or backwards (false) to initiate movement. Each sprint was started with an audio cue that also activated the timing gates. Three trials of each starting style were performed and movement (0 m), 2.5-, and 5-m times were recorded. An in-ground force plate placed at the 0-m mark measured the kinetic and temporal characteristics of the first step. Sprint times to 2.5 and 5 m were slower (p < 0.05) when a parallel start was used. No differences were seen in the normalized peak forces (vertical and horizontal) or the vertical impulse between starts, but the vertical mean force was 11 and 12% higher for the false and split starts, respectively. Surprisingly, the parallel start's impulse was significantly greater than that of the false (24%) and split (22%) styles, a consequence of the additional time spent in contact with the ground. The ground contact time, time to peak force, and time from peak force to toe-off (vertical and horizontal) were significantly longer for the parallel start. These temporal variables were also better correlated with sprint performance than any kinetic measure (0.42 ≤ r ≤ 0.75). The false start appears to be advantageous over short distances by improving push-off and the temporal characteristics of the first step.     

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.     

Repeated-sprint and effort ability in rugby league players

The aim of this study was to (a) investigate the influence of tackling on repeated-sprint performance; (b) determine whether repeated-sprint ability (RSA) and repeated-effort ability (REA) are 2 distinct qualities; and (c) assess the test-retest reliability of repeated-sprint and repeated-effort tests in rugby league. Twelve rugby league players performed a repeated-sprint (12 × 20-m sprints performed on a 20-second cycle) and a repeated-effort (12 × 20-m sprints with intermittent tackling, performed on a 20-second cycle) test 7 days apart. The test-retest reliability of these tests was also established. Heart rate and rating of perceived exertion were recorded throughout the tests. There was a significantly greater (p ≤ 0.05) and large effect size (ES) differences for total sprint time (ES = 1.19), average heart rate (ES = 1.64), peak heart rate (ES = 1.35), and perceived exertion (ES = 3.39) for the repeated-effort test compared with the repeated-sprint test. A large difference (ES = 1.02, p = 0.06) was detected for percentage decrement between the 2 tests. No significant relationship was found between the repeated-sprint and repeated-effort tests for any of the dependent variables. Both tests proved reliable, with total sprint time being the most reliable method of assessing performance. This study demonstrates that the addition of tackling significantly increases the physiological response to repeated-sprint exercise and reduces repeated-sprint performance in rugby league players. Furthermore, RSA and REA appear to be 2 distinct qualities that can be reliably assessed with total time being the most reliable measure of performance.     

The effects of sprint running training on sloping surfaces

The aim of this study was to examine the effects of sprint running training on sloping surfaces (3 degrees ) on selected kinematic and physiological variables. Thirty-five sport and physical education students were randomized into 4 training groups (uphill-downhill, downhill, uphill, and horizontal) and a control group, with 7 participants in each group. Pre- and posttraining tests were performed to examine the effects of 6 weeks of training on the maximum running speed at 35 m, step rate, step length, step time, contact time, eccentric and concentric phase of contact time, flight time, selected posture characteristics of the step cycle, and peak anaerobic power performance. Maximum running speed and step rate were increased significantly (p < 0.05) in a 35-m running test after training by 0.29 m.s(-1) (3.5%) and 0.14 Hz (3.4%) for the combined uphill-downhill group and by 0.09 m.s(-1) (1.1%) and 0.03 Hz (2.4%) for the downhill group, whereas flight time shortened only for the combined uphill-downhill training group by 6 milliseconds (4.3%). There were no significant changes in the horizontal and control groups. Overall, the posture characteristics and the peak anaerobic power performance did not change with training. It can be suggested that the novel combined uphill-downhill training method is significantly more effective in improving the maximum running velocity at 35 m and the associated horizontal kinematic characteristics of sprint running than the other training methods are.     

An SNP within the angiotensin-converting enzyme distinguishes between sprint and distance performing Alaskan sled dogs in a candidate gene analysis

The Alaskan sled dog offers a unique mechanism for studying the genetics of elite athletic performance. They are a group of mixed breed dogs, comprised of multiple common breeds, and a unique breed entity seen only as a part of the sled dog mix. Alaskan sled dogs are divided into 2 primary groups as determined by their racing skills. Distance dogs are capable of running over 1000 miles in 10 days, whereas sprint dogs run much shorter distances, approximately 30 miles, but in faster times, that is, 18-25 mph. Finding the genes that distinguish these 2 types of performers is likely to illuminate genetic contributors to human athletic performance. In this study, we tested for association between polymorphisms in 2 candidate genes; angiotensin-converting enzyme (ACE) and myostatin (MSTN) and enhanced speed and endurance performance in 174 Alaskan sled dogs. We observed 81 novel genetic variants within the ACE gene and 4 within the MSTN gene, including a polymorphism within the ACE gene that significantly (P value 2.38 × 10(-5)) distinguished the sprint versus distance populations.     

The effect of time of day on short-term maximal performance in obese and non-obese young men

The purpose of this study was to examine time-of-day effects on short-term performance in obese young men. In a balanced study design, 30 boys were divided into two groups: obese (OG; n = 15) and non-obese (CG; n = 15) groups. Both groups performed anaerobic tests of strength and power (squat-Jump, SJ; counter-movement jump, CMJ; 10-m sprint; and 30-m sprint) at 08:00 and 17:00 h on separate days. The results showed morning–evening differences in all variables in CG, with significant increases at 17:00 h (around the time of peak temperature) in comparison with 08:00 h (p < 0.01) for OG. However, such morning-evening differences were not found in the OG, except for the 30-m sprint. Obesity affects the diurnal variation on performances of 30-m sprint with a significant decrease in the evening for OG of 1.23% (p < 0.01). A correlation between anaerobic performance and oral temperature was observed only in the 30-m sprint test. In conclusion, the findings of the present study indicated that obesity is a problem that can affect circadian rhythms and performance in obese young men; therefore, preventing childhood obesity should become a top priority in efforts to improve performance and health.     

Knee joint strength ratios and effects of hip position in rugby players

Measures of knee joint function, although useful in predicting injury, can be misleading because hip position in traditional seated isokinetic tests is dissimilar to when injuries occur. This study aimed to determine the differences between seated and supine peak torques and strength ratios and examine the interaction of position with joint velocity. This was a cross-sectional, repeated measures study. Isokinetic knee extensor and flexor concentric and eccentric peak torque was measured seated and supine (10° hip flexion) at 1.04 and 3.14 rad·s(-1) in 11 Rugby players. Repeated measures analysis of variance and paired t-tests were used to analyze peak torques and strength ratios. Bonferroni post hoc, limits of agreement, and Pearson's correlation were applied. Seated peak torque was typically greater than that for supine for muscle actions and velocities. The values ranged from 109 ± 18 N·m (mean ± σ) for supine hamstring concentric peak torque at 1.04 rad·s(-1) to 330 ± 71 for seated quadriceps eccentric peak torque at 1.04 rad·s(-1). There was a significant position × muscle action interaction; eccentric peak torque was reduced more than concentric in the supine position. Knee joint strength ratios ranged from 0.47 ± 0.06 to 0.86 ± 0.23, with a significant difference in means between supine and seated positions for functional ratio at 3.14 rad·s(-1) observed; for seated it was 0.86 ± 0.23; and for supine, it was 0.68 ± 0.15 (p < 0.05). Limits of agreement for traditional and functional ratios ranged from 1.09 ×/÷ 1.37 to 1.13 ×/÷ 1.51. We conclude that hip angle affects isokinetic peak torques and knee joint strength ratios. Therefore, the hip angle should be nearer 10° when measuring knee joint function because this is more ecologically valid. Using similar protocols, sports practitioners can screen for injury and affect training to minimize injury.     

Complex training in ice hockey: the effects of a heavy resisted sprint on subsequent ice-hockey sprint performance

The aim of the study was to investigate the acute effect of a heavy resisted sprint when used as a preload exercise to enhance subsequent 25-m on-ice sprint performance. Eleven competitive ice-hockey players (mean ± SD: Age = 22.09 ± 3.05 years; Body Mass = 83.47 ± 11.7 kg; Height = 1.794 ± 0.060 m) from the English National League participated in a same-subject repeated-measures design, involving 2 experimental conditions. During condition 1, participants performed a 10-second heavy resisted sprint on ice. Condition 2 was a control, where participants rested. An electronically timed 25-m sprint on ice was performed before and 4 minutes after each condition. The results indicated no significant difference (p = 0.176) between pre (3.940 + 0.258 seconds) and post (3.954 + 0.261 seconds) sprint times in the control condition. The intervention condition, however, demonstrated a significant 2.6% decrease in times (p = 0.02) between pre (3.950 + 0.251 seconds) and post (3.859 + 0.288 seconds) test sprints. There was also a significant change (p = 0.002) when compared to the times of the control condition. These findings appear to suggest that the intensity and duration of a single resisted sprint in this study are sufficient to induce an acute (after 4 minutes of rest) improvement in 25-m sprint performance on ice. For those athletes wishing to improve skating speed, heavy resisted sprints on ice may provide a biomechanically suitable exercise for inducing potentiation before speed training drills.     

Relationship between traditional and ballistic squat exercise with vertical jumping and maximal sprinting

The purpose of this study was to quantify the magnitude of the relationship between vertical jumping and maximal sprinting at different distances with performance in the traditional and ballistic concentric squat exercise in well-trained sprinters. Twenty-one men performed 2 types of barbell squats (ballistic and traditional) across different loads with the aim of determining the maximal peak and average power outputs and 1 repetition maximum (1RM) values. Moreover, vertical jumping (countermovement jump test [CMJ]) and maximal sprints over 10, 20, 30, 40, 60, and 80 m were also assessed. In respect to 1RM in traditional squat, (a) no significant correlation was found with CMJ performance; (b) positive strong relationships (p < 0.01) were obtained with all the power measures obtained during both ballistic and traditional squat exercises (r = 0.53-0.90); (c) negative significant correlations (r = -0.49 to -0.59, p < 0.05) were found with sprint times in all the sprint distances measured when squat strength was expressed as a relative value; however, in the absolute mode, no significant relationships were observed with 10- and 20-m sprint times. No significant relationship was found between 10-m sprint time and relative or absolute power outputs using either ballistic or traditional squat exercises. Sprint time at 20 m was only related to ballistic and traditional squat performance when power values were expressed in relative terms. Moderate significant correlations (r = -0.39 to -0.56, p < 0.05) were observed between sprint times at 30 and 40 m and the absolute/relative power measures attained in both ballistic and traditional squat exercises. Sprint times at 60 and 80 m were mainly related to ballistic squat power outputs. Although correlations can only give insights into associations and not into cause and effect, from this investigation, it can be seen that traditional squat strength has little in common with CMJ performance and that relative 1RM and power outputs for both squat exercises are statistically correlated to most sprint distances underlying the importance of strength and power to sprinting.     

Effect of pre-performance lower-limb massage on thirty-meter sprint running

Massage is a commonly utilized therapy within sports, frequently intended as an ergogenic aid prior to performance. However, evidence as to the efficacy of massage in this respect is lacking, and massage may in some instances reduce force production. The aim of this study was to investigate the effect of massage on subsequent 30-m sprint running performance. Male university level repeat sprint sports players volunteered for the study (n = 37). After each of 3 treatment conditions, subjects completed a standardized warm-up followed by three 30-m sprint trials in a counterbalanced crossover design. Treatment conditions were 15 minutes of lower-limb massage (M), 15 minutes of placebo ultrasound (PU), and rest (R). Thirty-meter sprint times were recorded (including 10-m split times) for the 3 trials under each condition. Best times at 10 m (M: 1.85 +/- 0.09 seconds, PU: 1.84 +/- 0.11 seconds, R: 1.83 +/- 0.10 seconds) and 30 m (M: 4.41 +/- 0.27 seconds, PU: 4.39 +/- 0.28 seconds, R: 4.39 +/- 0.28 seconds) were not significantly different (p > 0.05). There was no significant treatment, trial, or interaction effect for 10- or 30-m sprint times (p > 0.05). No difference was seen in the location of subjects' best times across the 3 trials (p > 0.05). Relative to placebo or control, the results of this study showed that a controlled 15-minute lower-limb massage administered prior to warm-up had no significant effect on subsequent 30-m sprint performance. Massage remains indicated prior to performance where other benefits, such as reduced muscle spasm and psychological stress, might be served to the athlete.