Acute effect of whole body vibration combined with weighted vest on muscle strength and balance in elderly

Introduction: Both whole body vibration training (WBV) and training with a weighted vest (WV) have resulted in beneficial improvements in muscle strength and balance in the elderly. However, whether combining the two types of training (WBV+WV) elicit greater performance improvements is yet to be established. Purpose: To compare the physiological consequence of an acute bout of WBV, WV training or the combination of both (WBV+WV). Methods: Fifty-two healthy elderly volunteers (65.2 ± 3.7 years, mean ± SD) were randomly allocated into 3 groups: WBV (n = 17, high squat position with vibration frequency of 30 Hz and amplitude of low), WV (n = 16, additional 10% of body weight added while exercising in a high squat position) and a combination of both training regimes WBV+WV (n = 19, high squat position with additional 10% of body weight with vibration frequency of 30 Hz and amplitude of low). Participants exercised for 10 sets of 1 minute interspersed with a 1 minute rest between sets. Muscular strength (maximal isometric force, MVC) and performance tests (single-leg stance, time up and go test) were completed before and 15 minutes post exercise. Results and Discussion: All three groups significantly improved time up and go test (5.4% for WBV, 4.0% for weight vest and 4.4% for WBV combined weighted vest, p < 0.01). In WBV group, there was significantly increased leg muscle strength (11%, p < 0.01) and single leg stance test (65.3%, p < 0.01), while there was no significant change of muscle strength in weighted vest (3.3%, p = 0.37) and WBV combined with weighted vest groups (4.7%, p = 0.10), and single leg stance test in weighted vest (- 13.0%, p = 0.33) and WBV combined weighted vest groups (42.4%, p = 0.06). Additionally, there was no significant difference of all outcomes compared between three groups. Conclusions: All three groups had beneficial effect on time up and go test. While WBV alone has greater positive acute effect on leg muscle strength, and single leg stance test. Training effects of three groups should be investigated in the further study