Acute physiological effects of exhaustive whole-body vibration exercise inman

Vibration exercise (VE) is a new neuromuscular training method which is app lied in athletes as well as in prevention and therapy of osteoporosis. The present study explored the physiological mechanisms of fatigue by VE in 37 young healthy subjects. Exercise and cardiovascular data were compared to p rogressive bicycle ergometry until exhaustion. VE was performed in two sess ions, with a 26 Hz vibration on a ground plate, in combination with squatti ng plus additional load (40% of body weight). After VE, subjectively percei ved exertion on Borg's scale was 18, and thus as high as after bicycle ergo metry. Heart rate after VE increased to 128 min(-1), blood pressure to 132/ 52 mmHg, and lactate to 3.5 mM. Oxygen uptake in VE was 48.8% of VO2max in bicycle ergometry. After VE, voluntary force in knee extension was reduced by 9.2%, jump height by 9.1%, and the decrease of EMG median frequency duri ng maximal voluntary contraction was attenuated. The reproducibility in the two VE sessions was quite good: for heart rate, oxygen uptake and reductio n in jump height, correlation coefficients of values from session 1 and fro m session 2 were between 0.67 and 0.7. Thus, VE can be well controlled in t erms of these parameters. Surprisingly, an itching erythema was found in ab out half of the individuals, and an increase in cutaneous blood flow. It fo llows that exhaustive whole-body VE elicits a mild cardiovascular exertion, and that neural as well as muscular mechanisms of fatigue may play a role.