Performance during human movements is highly related to force and velocity muscle capacities. Those capacities are highly developed in elite athletes practicing power-oriented sports. However, it is still unclear whether the balance between their force and velocity-generating capacities constitutes an optimal profile. In this study, we aimed to determine the effect of elite sport background on the force–velocity relationship in the squat jump, and evaluate the level of optimization of these profiles. Ninetyfive elite athletes in cycling, fencing, taekwondo, and athletic sprinting, and 15 control participants performed squat jumps in 7 loading conditions (range: 0%–60% of the maximal load they were able to lift). Theoretical maximal power (Pm), force (F 0), and velocity (v 0) were determined from the individual force–velocity relationships. Optimal profiles were assessed by calculating the optimal force (F 0th) and velocity (v 0th). Athletic sprinters and cyclists produced greater force than the other groups (P < .05). F 0 was significantly lower than F 0th, and v 0 was significantly higher than v 0th for female fencers and control participants, and for male athletics sprinters, fencers, and taekwondo practitioners (P < .05). Our study shows that the chronic practice of an activity leads to differently balanced force–velocity profiles. Moreover, the differences between measured and optimal force–velocity profiles raise potential sources of performance improvement in elite athletes.
Caroline Giroux, Giuseppe Rabita, Didier Chollet and Gaël Guilhem
Enzo Hollville, Vincent Le Croller, Yoshihiro Hirasawa, Rémi Husson, Giuseppe Rabita and Franck Brocherie
Purpose: To evaluate the effect of multiple sets of repeated-sprint-ability (RSA)-induced fatigue on subsequent passing-skill performance in field hockey players. Methods: A total of 10 elite U-21 (under-21) male field hockey players performed 5 sets of a combination of RSA test (6 × 20 m, 20 s of passive recovery) followed by a 1-min passing-skill test (passing reception with subsequent passes at a predesigned target). Data on fastest sprint time and cumulated sprint time for RSA test; total number of balls played, targeted, and passing accuracy (number of balls targeted/total number of balls played) for passing-skill test; heart rate (HR), blood lactate concentration (BLa), and rating of perceived exertion (RPE) were collected throughout the protocol. Results: RSA performance was significantly impaired from set 1 to set 5 (fastest sprint time +4.1%, P < .001; cumulated sprint time +2.3%, P < .01). For a similar average number of balls played (12.8 [1.4]) during each set, number of balls targeted (−1.7%, P < .05) and passing accuracy (−3.1%, P < .05) decreased up to the third set before reimproving over the last 2 sets. Psychophysiological responses (HR, BLa, and RPE) progressively increased (P < .05) toward protocol cessation. The decrease in passing accuracy with increasing RSA cumulated sprint time was fitted to a 2nd-order polynomial function (r 2 = .94, P < .05). Conclusion: Multiple-set RSA-induced fatigue was accompanied by passing-skill adjustment variation, suggesting a complex interaction between physiological and psychological/cognitive function to preserve passing skill under fatigued condition.