Changes in repeated-sprint performance in relation to change in locomotor profile in highly-trained young soccer players

How to use changes in non soccer-specific locomotor entities (i.e., maximal aerobic and sprinting speeds) to predict changes in performance that is believed to be soccer specific (although I have my doubts too!)

Figure 1Buchheit, M. and Mendez-Villanueva, A., Changes in repeated-sprint performance in relation to change in locomotor profile in highly-trained young soccer players, J Sports Sci., 2014, In press

To examine the effects of changes in maximal aerobic (MAS) and sprinting (MSS) speeds, and the anaerobic reserve (ASR), on repeated-sprint performance, 270 highly-trained soccer players (14.5±1.6 yr) completed three times per season (over 5 years) a maximal incremental running test to approach MAS, a 40-m sprint with 10-m splits to assess MSS and a repeated-sprint test (10×30-m sprints), where best (RSb) and mean (RSm) sprint times, and percentage of speed decrement (%Dec) were calculated. ASR was calculated as MSS-MAS. While ∆RSb were related to ∆MSS and ∆body mass (r2=0.42, 90%CL[0.34;0.49] for the overall multiple regression, n=334), ∆RSm was also correlated with ∆MAS and ∆sum of 7 skinfolds (r2 =0.43 [0.35;0.50], n=334). ∆%Dec was related to ∆MAS (r2=0.02 [-0.07;0.11], n=334). Substantial ∆MSS and ∆MAS had a predictive value of 70 and 55% for ∆RSm, respectively. Finally, ∆ASR per se was not predictive of ∆RSm (Cohen’s = +0.8 to -0.3 with increased ASR), but the greater magnitude of ∆RSm improvement was observed when MSS, MAS and ASR increased together (0.8 vs. +0.4 with ASR increased vs. not, additionally to MSS and MAS). Low-cost field tests aimed at assessing maximal sprinting and aerobic speeds can be used to monitor ∆RS performance.

Key words: football association; repeated-sprint ability; maximal sprinting speed; maximal aerobic speed; anaerobic speed reserve

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Body Dimensions of Elite Handball Players

Karcher, C, Ahmaidi S and Buchheit M. Body Dimensions of Elite Handball Players With  Respect To Laterality, Playing Positions and Playing Standard. Journal of Athletic Enhancement SciTechnol, 2014, In press.

Abstract

Purpose: The aim of the present study was to examine, using a large player database, between-playing positions and playing standard differences in body dimensions.

Methods: We compared stature and body mass of 1295 male elite handball players from different playing positions, i.e., backs (left and right), center backs, goalkeepers, pivots, wings (left and right) and playing standards (European championship, Champions league matches and national leagues from Germany, Spain and France).

Results: When all playing standards were pooled together, wings (left 185±6cm, right 185±6cm) were almost certainly slightly-to-moderately shorter than center backs (188±5 cm), which were slightly-to-largely shorter than backs (left 196±5cm, right 194±5cm), pivots (194±6cm) and goalkeepers (193±5cm). Pivots (100.1±9.1kg) were almost certainly slightly-to-very-largely heavier than the other positions, with backs (left 95.1±7.6kg, right 92.5±8kg) and goalkeepers (93.5±8.5kg) being moderately-to-largely heavier than wings (left 83.3±7.8kg, right 82.1±7kg) and center backs (88±7.6kg). Center, left and right backs were almost certainly slightly-to-moderately taller in the European championships, goalkeepers and right wings in Champions league, left backs in the German first league and pivots in the Spanish first league. Center and left backs were almost certainly slightly-to-moderately heavier in the European championship. Left wings were almost certainly slightly heavier in the German first league and pivots in the Spanish first league.

Conclusions: These data show the importance of considering players’ laterality when assessing their body dimensions. They might also serve as anthropometric benchmarks when profiling talented young players.

Key words: stature; body mass; anthropometric benchmarks; talent identification; players selection.

19e8f14d0fefc1da546be244d2de8960_400x400@ALDOLITO

Sensitivity of heart rate and psychometric measures to monitor physical performance in handball

Buchheit, M. Sensitivity of heart rate and psychometric measures to monitor physical performance in handball. Int J Sports Med, 2014, In press. Full text herecropped-bandeauAbstract  The aim of the present study was to examine whether monthly resting heart rate (HR), HR variability (HRV) and psychometric measures can be used to monitor changes in physical performance in highly-trained adolescent handball players. Data were collected in 37 adolescent players (training 10±2.1 h.wk-1) at 11 occasions from September to May during the in-season period, and included an estimation of training status (resting HR and HRV, the profile of mood state (POMS) questionnaire), and three physical performance tests (a 10-m sprint, a counter movement jump and a graded aerobic intermittent test, 30-15 Intermittent Fitness Test). The sensitivity of HR and psychometric measures to changes in physical performance was poor (<20%), irrespective of the training status markers and the performance measures. The specificity was however strong (>75%) irrespective of the markers and the performance measures. Finally, the difference in physical performance between players with better vs. worse estimated training status were all almost certainly trivial. The present results highlight the limitation of monthly measures of resting HR, HRV and perceived mood and fatigue to predict in-season changes in physical performance in highly-trained adolescent handball players. This suggests that more frequent monitoring might be required, and/or that other markers might need to be considered. Key words: heart rate variability; POMS; speed tests; counter movement jump, 30-15 Intermittent Fitness Test; progressive statistics.