A comparison of the physiologic effects of acute whole-body vibration exercise in young and older people

Objective: To examine the acute physiologic effects of acute whole-body vibration (WBV) exercise in young and older people. Design: Every participant performed 9 conditions in a static squat position, consisting of no vibration and WBV at 30Hz and 3 loads corresponding to (1) no load (0% body mass), (2) load of 20% body mass, and (3) load of 40% body mass. A Jendrassik voluntary contraction was also performed with no vibration and WBV at 30Hz with no load and 20% body mass. Setting: Laboratory facilities at a university in the United Kingdom. Participants: Healthy young people (n=12; 6 men, 6 women; mean age, 21.5y) and 12 healthy older people (6 men, 6 women; mean age, 69.2y) from the local community. Interventions: Not applicable. Main Outcome Measures: The Physical Activity Questionnaire, anthropometric measures, counter-movement jump, and isometric maximal voluntary contraction with the Jendrassik maneuver were assessed in both groups. Oxygen uptake (V̇o2), blood pressure, heart rate, and rating of perceived exertion (RPE) were recorded during WBV and load conditions as the outcome of the study. Results: Both vibration and load were associated with an increase (P<.001) in V̇o2 for older and young groups. WBV elicited the equivalent of a .35 metabolic equivalent (MET) increase in V̇o2, with additional loads of 20% and 40% body mass increasing V̇o2 by 0.8 and 1.2 METs, respectively. Additionally, there was an interaction effect of vibration and group in which the WBV-related V̇o2 increase was less in the old compared with the young. Both vibration and load caused an increase in heart rate, blood pressure, and RPE (all P<.001); however, there were no significant group differences between young and older groups. The Jendrassik maneuver elicited an increase in V̇o2 by 27.6% for the old and 33% for the young group (P<.001); however, there was no significant difference between groups. Conclusions: V̇o2 significantly increased in both the older and young people with vibration and additional load and when the Jendrassik maneuver was superimposed with vibration and load. However, the elicited increase in V̇o2 (1.2mL·kg-1·min-1) from WBV may be an insufficient stimulus to improve cardiovascular fitness.