Monday, June 30, 2008

Repeated Sprint Ability

Effect of recovery mode on repeated sprint ability in young basketball players.
J Strength Cond Res. 2008 May;22(3):923-9.

The aim of this study was to examine the effect of recovery mode on repeated sprint ability in young basketball players. Sixteen basketball players (age, 16.8 +/- 1.2 years; height, 181.3 +/- 5.7 cm; body mass, 73 +/- 10 kg; VO2max, 59.5 +/- 7.9 mL x kg(-1) x min(-1)) performed in random order over 2 separate occasions 2 repeated sprint ability protocols consisting of 10 x 30-m shuttle run sprints with 30 seconds of passive or active (running at 50% of maximal aerobic speed) recovery. Results showed that fatigue index (FI) during the active protocol was significantly greater than in the passive condition (5.05 +/- 2.4, and 3.39 +/- 2.3, respectively, p < 0.001). No significant association was found between VO2peak and FI and sprint total time (TT) in either repeated sprint protocols. Blood lactate concentration at 3 minutes post exercise was not significantly different between the 2 recovery conditions. The results of this study show that during repeated sprinting, passive recovery enabled better performance, reducing fatigue. Consequently, the use of passive recovery is advisable during competition in order to limit fatigue as a consequence of repeated high intensity exercise.

Relationship between measured maximal oxygen uptake and aerobic endurance performance with running repeated sprint ability in young elite soccer players.
J Sports Med Phys Fitness. 2007 Dec;47(4):401-7.

AIM: The aim of the study was to determine the relationships between maximal oxygen uptake (VO(2max)) in a maximal treadmill run and the aerobic endurance performance in the 20-m multistage shuttle run (MST) test, with the performance indices obtained in the running repeated sprint ability (rRSA) test, in elite youth soccer players. METHODS: Thirty-seven adolescent male outfield players performed on separate days and in random order the treadmill run test and the MST, to obtain their measured VO(2max) and aerobic endurance performance (via the number of completed shuttles in the MST), respectively. Players also completed the rRSA test of 6x20-m all-out sprints, interspersed with 20 s of active recovery. RESULTS: There was a significant moderate correlation between measured VO(2max) (in L . min(-1) and mL . kg(-1) . min(-1)) and MST results (r=0.43 and 0.54, P<0.05, respectively). There was no significant correlation between measured VO(2max) and aerobic endurance performance with any of the performance indices in the rRSA test (all P>0.05). CONCLUSION: The moderate association between the measured VO(2max) and MST suggests that both tests were plausibly measuring different aspects of a player's aerobic fitness. The lack of association between measured VO(2max) and aerobic endurance performance in the MST with performance in the rRSA suggests that aerobic fitness per se is poorly associated with performance in the rRSA in elite youth soccer players.

Sprint vs. Interval Training in Football.
Int J Sports Med. 2007 Dec 17. [Epub ahead of print]

The aim of this study was to compare the effects of high-intensity aerobic interval and repeated-sprint ability (RSA) training on aerobic and anaerobic physiological variables in male football players. Forty-two participants were randomly assigned to either the interval training group (ITG, 4 x 4 min running at 90 - 95 % of HR (max); n = 21) or repeated-sprint training group (RSG, 3 x 6 maximal shuttle sprints of 40 m; n = 21). The following outcomes were measured at baseline and after 7 weeks of training: maximum oxygen uptake, respiratory compensation point, football-specific endurance (Yo-Yo Intermittent Recovery Test, YYIRT), 10-m sprint time, jump height and power, and RSA. Significant group x time interaction was found for YYIRT (p = 0.003) with RSG showing greater improvement (from 1917 +/- 439 to 2455 +/- 488 m) than ITG (from 1846 +/- 329 to 2077 +/- 300 m). Similarly, a significant interaction was found in RSA mean time (p = 0.006) with only the RSG group showing an improvement after training (from 7.53 +/- 0.21 to 7.37 +/- 0.17 s). No other group x time interactions were found. Significant pre-post changes were found for absolute and relative maximum oxygen uptake and respiratory compensation point (p < 0.05). These findings suggest that the RSA training protocol used in this study can be an effective training strategy for inducing aerobic and football-specific training adaptations.

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