Acute and cumulative effects of focused high-frequency vibrations on the endocrine system and muscle strength
This study reveals that the high-frequency vibration treatment (300 Hz) leads to a significant increase in the levels of growth
hormone and creatin-kinase, which is important for energy production in the muscle, and to a reduction in the levels of cortisol, the so-called stress hormone.
It has been also noticed a significant increase in the maximal voluntary contraction, which indicates that the tratment enhances the muscle’s strength development ability.
Benefits similar to a resistance training are obtained. Results last to the end of the 2 months-follow up.
The purpose of this study was to evaluate the acute and long-term effects of local high-intensity vibration (HLV, f = 300 Hz) on muscle performance and blood hormone concentrations in healthy young men. Totally 18 subjects (cV group) were studied in two sessions, either without (control) or with HLV treatment. The protocol was the same on both control and test days, except that, in the second session, subjects underwent HLV treatment. Counter-movement jumping (CMJ), maximal isometric voluntary contraction (MVC) test, and hormonal levels were measured before the procedure, immediately thereafter, and 1 h later. To assess the long-term effects of HLV, the cV group was subjected to HLV on the leg muscles for 4 weeks, and a second group (cR group, n = 18) embarked upon a resistance training program. All subjects underwent an MVC test and an isokinetic (100 deg/s) test before training, 4 weeks after training, and 2 months after the end of training. The HLV protocol significantly increased the serum level of growth hormone (GH, P\0.05) and creatine phosphokinase (CPK, P\0.05), and decreased the level of cortisol (P\0.05). None of GH, CPK or testosterone levels were altered in controls. There was a significant improvement in MVC (P\0.05). After 4 weeks, both the cV and cR groups demonstrated significant improvement in MVC and isokinetic tests (P\0.05). This increase persisted for at least 2 months. Our results indicate that HLV influences the levels of particular hormones and improves neuromuscular performance. Our results indicate that HLV has a long-term beneficial effect comparable to that of resistance training.
Keywords High-intensity local vibration, Growth hormone, Testosterone, Muscle strength, Jumping performance
Source: P. Iodice et al, Acute and cumulative effects of focused high-frequency vibrations on the endocrine system and muscle strength, European Journal of Applied Physiology, 2011 Jun;
© Springer-Verlag 2010