Effect of whole-body vibration training on body composition, exercise performance and biochemical responses in middle-aged mice

Whole-body vibration (WBV) is a well-known light-resistance exercise by automatic adaptations to rapid and repeated oscillations from a vibrating platform, which is also a simple and convenient exercise for older adults. However, the potential benefits of WBV on aging-associated changes in body composition, exercise performance, and fatigue are currently unclear. The objective of the study is to investigate the beneficial effects of WBV training on body composition, exercise performance, and physical fatigue-related and biochemical responses in middle-aged mice.In total, 24 male C57BL/6 mice aged 15 months old were randomly divided into 3 groups (n=8 per group): sedentary control (SC), relatively low-frequency WBV (5.6 Hz, 2 mm, 0.13 g) (LV), and relatively high-frequency WBV (13 Hz, 2 mm, 0.68 g) (HV). Mice in the LV and HV groups were placed inside a vibration platform and vibrated at different frequencies and fixed amplitude (2 mm) for 15 min, 5 days/week for 4 weeks. Exercise performance, core temperature and anti-fatigue function were evaluated by forelimb grip strength and levels of serum lactate, ammonia, glucose, and creatine kinase (CK) after a 15-min swimming exercise, as were changes in body composition and biochemical variables at the end of the experiment.Relative muscle and brown adipose tissue weight (%) was significantly higher for the HV than SC mice, but relative liver weight (%) was lower. On trend analysis, WBV increased grip strength, aerobic endurance and core temperature in mice. As well, serum lactate, ammonia and CK levels were dose-dependently decreased with vibration frequency after the swimming test. Fasting serum levels of albumin and total protein were increased and serum levels of alkaline phosphatase and creatinine decreased dose-dependently with vibration frequency. Moreover, WBV training improved the age-related abnormal morphology of skeletal muscle, liver and kidney tissues. Therefore, it could improve exercise performance and ameliorate fatigue and prevent senescence-associated biochemical and pathological alterations in middle-aged mice.WBV training may be an effective intervention for health promotion in the aging population. The detailed molecular mechanism of how WBV training regulates anti-aging activity warrants further functional studies.