| Autor: |
Gimenez P; Laboratoire C3S (EA 4660), Université de Bourgogne-Franche-Comté, Besançon, France.; École de kinésiologie et des sciences de l'activité physique, Université de Montréal, Montréal, Canada., Chicoine E; École de kinésiologie et des sciences de l'activité physique, Université de Montréal, Montréal, Canada., Amarantini D; ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France., Maso FD; École de kinésiologie et des sciences de l'activité physique, laboratoire de simulation et modélisation du mouvement, Université de Montréal, Montréal, Canada., Tremblay J; École de kinésiologie et des sciences de l'activité physique, Université de Montréal, Montréal, Canada.; Institut National du Sport du Québec, Montréal, Canada. |
| Abstrakt: |
The 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 corresponding repeated jumps. The results showed that PO was significantly greater during the test in COND than in CTRL ( p <0.01). PO significantly decreased with sets, by 19.4±4.7 and 15.2±7.6% ( p <0.001) between the first and last set in COND and CTRL, respectively. A 2×3 s maximal unilateral isometric CC, performed 5 min before unloaded repeated jumps, significantly increased mean PO. These results suggest that unilateral conditioning contractions can enhance performance in subsequent bilateral repeated jumps. |
