Acute and cumulative effects of focused high-frequency vibrations on the endocrine system and muscle strength

Abstract

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.

Effect of combined treatment with focused mechanoacoustic vibration and pharmacological therapy on bone mineral density and muscle strength in post-menopausal women

“…For example, using high-frequency focal vibration, we reached the normalization of the basal tone in two heads of the quadriceps femoris muscle (rectus femoris and vastus medialis) in ten sporting subjects (38). In another study, sarcopenic thigh muscles submitted to local vibrational training at 300 Hz for a period of 12 weeks, starting with a session of 15 min stimulation once a week and increasing to three sessions of 15 min per week, displayed enhanced maximal isometric strength and increased content of fast MyHC-2X myosin, without any change in cross-sectional area or in specific tension; analysis of transcriptional profiles by microarray revealed changes in gene expression after 12 weeks of local vibrational training, in particular pathways related with energy metabolism, sarcomeric protein balance and oxidative stress response were affected: thus, the mode of action of vibration is based on cellular and molecular changes which do not include increase in fiber or muscle size (39), but affects serum level of growth hormone, creatine phosphokinase (increase) and cortisol (decrease) (40). Moreover, using the focused mechano-acoustic vibration at 300 Hz, it has been also shown that a 12-week training is equivalent to a global sensorimotor and a resistance training (60-80% of maximum theoretical force, 10-12 repetitions for 3 sets, 2 sessions per week) in improving balance, with a reduction of sway area and of ellipse surface, and in increasing the length of half-step and reducing the width of the support at the gait analysis, with reduction of the risk of falls in the sarcopenic elderly subjects enrolled in the study (41).…”

The acute effects of local muscle vibration frequency on peak torque, rate of torque development, and EMG activity

“…However, commercially available WBV platforms are cost prohibitive and provide limited portability. Local muscle vibration (LMV) applied directly to the muscle-tendon unit also influences muscle function (Bongiovanni and Hagbarth, 1990;Couto et al, 2013;Iodice et al, 2011;Mischi and Cardinale, 2009;Ribot-Ciscar et al, 2003), and may provide a cost effective and portable alternative to WBV. For example, Couto et al (2013), found that maximal voluntary contraction of the quadriceps improved after 4 weeks of 8 Hz and 26 Hz LMV.…”

Neural adaptations in quadriceps muscle after 4 weeks of local vibration training in young versus older subjects

“…found to increase by ~7-10% (Lapole and Pérot 2010;Lapole et al 424 2013) to ~30%(Iodice et al 2011) in healthy young subjects, while similar results 425 (+~14%) were found in healthy old subjects(Tankisheva et al 2015). Since training 426 parameters used in this later study differed from ours, e.g.…”