The aim of this study was to compare the immediate effects of cold-water immersion (CWI) and hot-water immersion (HWI) versus passive resting after a fatigue-induced bout of exercise on the muscle contractile properties of the Vastus Medialis (VM). We conducted a randomised cross-over study involving 28 healthy active men where muscle contractile properties of the VM wer recorded using Tensiomyography (TMG) before and after CWI, HWI or passive resting and up to one-hour post-application. The main outcomes obtained were muscle displacement and velocity of deformation according to limb size (Dmr and Vdr). Our results showed a significant effect of time (F(3.9,405) =32.439; p <0.001; η2p =0.29) and the interaction between time and temperature (F(7.9,405) =5.814; p <0.001; η2p=0.13) on Dmr but no for temperature alone (F(2,81) =2.013; p =0.14; η2p=0.04) while for Vdr, both time (F(5.2,486) =23.068; p <0.001 η2p = 0.22) and temperature (F(2,81) =4.219; p = 0.018; η2p= 0.09) as well as the interaction (F(10.4,486) =7.784; p <0.001; η2p =0.16) were found significant. Compared to CWI, HWI increased Dmr post-application and Vdr both post-application as well as 15 and 45' thereafter. These findings suggest that applying HWI could be a valid alternative to CWI to promote muscle recovery.
Keywords: Mechanomyography – water immersion – muscle contractile properties – exercise recovery.