0000000000609602
AUTHOR
Philippe Gimenez
Sprint Acceleration Mechanics in Fatigue Conditions: Compensatory Role of Gluteal Muscles in Horizontal Force Production and Potential Protection of Hamstring Muscles.
Aim: Hamstring muscle injury is the main injury related to sports requiring sprint acceleration. In addition, hamstring muscles have been reported to play a role in horizontal force production during sprint acceleration performance. The aim of the present study was to analyze (i) the determinants of horizontal force production and (ii) the role of hip extensors, and hamstring muscles in particular, for horizontal force production during repeated sprint-induced fatigue conditions. Method: In this experimental laboratory setting study including 14 sprint-trained male athletes, we analyzed (i) the changes in sprint mechanics, peak torque of the knee and hip extensors and flexors, muscle activi…
Unilateral Conditioning Contractions Enhance Power Output in Elite Short Track Speed Skaters
AbstractThe objective of the present study was to assess the effect of unilateral lower-body-conditioning muscle contractions during multiple sets of fatiguing repeated jumps in elite athletes. Five elite short-track speed-skating athletes performed 9 sets of 6 maximal consecutive jumps on 2 separate occasions: with (COND) and without (CTRL) preliminary voluntary conditioning contractions (CC) 5 min before the beginning of the sets. The CC consisted of 2 consecutive 3 s maximal unilateral isometric squats against a fixed bar, resulting in a 6 s overall isometric contraction per leg. For each set, power output (PO) was measured using a linear position transducer and averaged over the 6 corre…
Physiological responses and parasympathetic reactivation in rescue interventions: The effect of the breathing apparatus.
This study aimed to assess the effect of wearing a breathing apparatus during a simulated rescue intervention on psychophysiological responses and parasympathetic reactivation of firefighters. Thirty-four firefighters participated in this study which consisted of four experimental sessions conducted randomly: a maximal fitness test and three rescue interventions performed (a) with personal protective clothing (PPC); (b) with PPC and the full self-contained breathing apparatus (SCBA), including cylinder, full-face piece, and breathing regulator; and (c) with PPC and only the cylinder of the self-contained breathing apparatus (SCBAc). Physiological (heart rate [HR], breathing frequency [BF]) …