Effects of whole-body vibration under hypoxic exposure on muscle mass and functional mobility in older adults.

Abstract

Ageing is accompanied by a loss of muscle mass and function, which are associated with decrease of functional capacity. Combination of WBV training with normobaric hypoxic exposure could augment the beneficial effects due to synergic effects of both treatments. The purpose of this study was to examine the effects of 36 sessions of the combined WBV training and normobaric hypoxic exposure on muscle mass and functional mobility in older adults. Nineteen elderly people were randomly assigned to a: vibration normoxic exposure group (NWBV; n = 10; 20.9% FiO2) and vibration hypoxic exposure group (HWBV; n = 9). Participants developed 36 sessions of WBV training along 18weeks, which included 4 bouts of 30s (12.6Hz in frequency and 4mm in amplitude) with 60s of rest between bouts, inside a hypoxic chamber for the HWBV. The "Timed Up and Go Test" evaluated functional mobility. Percentages of lean mass were obtained with dual-energy X-ray absorptiometry. Neither statistically significant within group variations nor statistically significant differences between both groups were detected to any parameter. Baseline characteristics of population, training protocol and the level of hypoxia employed could cause different adaptations on muscle mass and function. The combination of WBV training and hypoxic exposure did not cause any effect on either legs lean mass or functional mobility of older adults.