Résumé
The gains made by muscle strengthening are obtained thanks to mechanical stress, but also metabolic by relative muscular hypoxia. Recently, the scientific community has shown increasing interest in strengthening methods under partial muscle ischemia, which seem to be a new alternative in complex rehabilitation situations due to the lower load applied to the joint and the tendons. The aim of this study was to compare the hemodynamic and oxygenation responses of the hamstring muscles between an exercise protocol (6 movements) combining alternating regimens of eccentric (Exc) and concentric (Con) muscle contractions without a rest phase, and an Exc/Con protocol in cuff occlusion (BFR), with a rest phase equal to the working time between each contraction.Materials and methods: randomized clinical trial, during which 12 participants performed two equivalent working methods (30% of peak torque Exc/Con without rest, 30% of peak torque Exc/passive alternated with passive/Con, with rest) on an isokinetic dynamometer (CON-TREX). Variations in blood volume and muscle oxygenation were quantified by a near-infrared spectroscopy device (NIRS PortaLite) positioned at the level of the hamstrings.Results: the mean values of tHb and HHb varied equally, as did the extent of the TSI (TOST procedure for Two One-Sided Tests) between contractions without rest and those with a pressure cuff. The perception of effort was lower for the EXCON condition (8-9 on the Borg scale).Conclusion: these results suggest a lower blood flow and an increase in muscle deoxygenation during an absence of a resting phase, leading to a level of ischemia equivalent to that obtained by Blood Flow Restriction. These results make it possible to consider the development of low-intensity muscle strengthening programs without a rest phase, which can be useful either in post-injury muscle healing or in primary or secondary prevention.