gms | German Medical Science

Aging has been associated with a decline in muscle mass and muscle strength, referred to as sarcopenia. Sarcopenia is accompanied by decreased mobility, increased fall risk, loss of independence, resulting in an impaired quality of life. Strength training appears to be effective to slow down the effects of ageing on muscle tissue but is not attractive for most elderly and may induce injuries. Whole Body Vibration (WBV) training might be an alternative by showing promising results on muscle strength both in younger and older women. However, data about the effect on muscle performance in older men are lacking and so far there are no studies addressing the possible hyperthrophic adaptations of long term WBV training.

This randomized controlled trial investigated the effects of one year WBV training on isometric and explosive muscle strength and on muscle mass in community dwelling men over the age of 60. 93 men were randomly assigned to a WBV group (n=31, 67.2±0.7years), a Fitness group (n=30, 67.5±0.8years) or a Control group (n=32, 68.3±1.1years). The WBV group exercised during maximum 40 minutes (squat, deep squat, lunge, …) on a platform (Powerplate) that generates vertical sinusoidal vibrations. The mechanical stimuli stimulate the muscle spindles in leg muscles, which in turn activates the alpha-motor neurons, resulting in muscle contractions comparable to the tonic vibration reflex. The Fitness group performed cardiovascular, strength, balance and stretching exercises for 1.5 hours. The Control group did not participate in any training. Measurements were performed at baseline and after one year. Isometric knee extension strength was measured using an isokinetic dynamometer (Biodex), explosive muscle strength was assessed by a counter movement jump and muscle mass of the upper leg was determined by computed tomography (Siemens Sensation 16). Data were analysed by repeated measures ANOVA and contrastanalysis was used to assess between- and within-group differences.

WBV training enhanced isometric and explosive muscle strength significantly (+9.8%, p=0.005 and +10.9%, p<0.001 respectively) and improved muscle mass (+3.4%, p<0.001) The Fitness group also improved in isometric and explosive muscle strength (+13.1%, p<0.001 and +9.8%, p<0.001 respectively) and in muscle mass (+3.8%, p<0.001). Training effects were not significantly different between the WBV and Fitness group (p>0.05). No significant changes were found for the Control group (p>0.05).

WBV training is as efficient as a Fitness program to increase muscle strength and muscle mass in older men. The present findings demonstrate that the strength improvements after long term WBV training result from a combination of neural and hypertrophic adaptations. WBV training might have great potential to prevent/reverse sarcopenia in elderly. In contrast with a general fitness training program, WBV training minimizes the need for conscious exertion and stress on the musculoskeletal, respiratory and cardiovascular systems.