André Rosenberger

Vascular adaptations induced by 6 weeks WBV resistance exercise training.

The impact of whole‐body vibration (WBV) upon the cardiovascular system is receiving increasing attention. Despite numerous studies addressing the acute cardiovascular effects of WBV training, very little is known regarding long‐term adaptations in healthy humans.

EMG and heart rate responses decline within 5 days of daily whole-body vibration training with squatting.

In this study, we examined the acute effects of a 5-day daily whole-body vibration (WBV) training on electromyography (EMG) responses of the m. rectus femoris and m. gastrocnemius lateralis, heart rate (HR, continuously recorded), and blood lactate levels. The purpose of the study was to investigate the adaptation of muscle activity, heart rate and blood lactate levels during 5 days of daily training. Two groups of healthy male subjects performed either squat exercises with vibration at 20 Hz on a side alternating platform (SE+V, n = 20, age  = 31.9±7.5 yrs., height  = 178.8±6.2 cm, body mass  = 79.2±11.4 kg) or squat exercises alone (SE, n = 21, age  = 28.4±7.3 years, height  = 178.9±7.4 cm, body mass  = 77.2±9.7 kg). On training day 1, EMG amplitudes of the m. rectus femoris were significantly higher (P<0.05) during SE+V than during SE. However, this difference was no longer statistically significant on training days 3 and 5. The heart rate (HR) response was significantly higher (P<0.05) during SE+V than during SE on all training days, but showed a constant decline throughout the training days. On training day 1, blood lactate increased significantly more after SE+V than after SE (P<0.05). On the following training days, this difference became much smaller but remained significantly different. The specific physiological responses to WBV were largest on the initial training day and most of them declined during subsequent training days, showing a rapid neuromuscular and cardiovascular adaptation to the vibration stimulus.

Whole-Body Vibrations Do Not Elevate the Angiogenic Stimulus when Applied during Resistance Exercise

Knowledge about biological factors involved in exercise-induced angiogenesis is to date still scanty. The present study aimed to investigate the angiogenic stimulus of resistance exercise with and without superimposed whole-body vibrations. Responses to the exercise regimen before and after a 6-week training intervention were investigated in twenty-six healthy male subjects. Serum was collected at the initial and final exercise sessions and circulating levels of matrix metalloproteinases (MMP) -2 and -9, Vascular Endothelial Growth Factor (VEGF) and endostatin were determined via ELISA. Furthermore, we studied the proliferative effect of serum-treated human umbilical vein endothelial cells in vitro via BrdU-incorporation assay. It was found that circulating MMP-2, MMP-9, VEGF and endostatin levels were significantly elevated (P<0.001) from resting levels after both exercise interventions, with higher post-exercise VEGF concentrations in the resistance exercise (RE) group compared to the resistive vibration exercise (RVE) group. Moreover, RE provoked increased endothelial cell proliferation in vitro and higher post-exercise circulating endostatin concentrations after 6 weeks of training. These effects were elusive in the RVE group. The present findings suggest that resistance exercise leads to a transient rise in circulating angiogenic factors and superimposing vibrations to this exercise type might not further trigger a potential signaling of angiogenic stimulation in skeletal muscle.

Microcirculation of skeletal muscle adapts differently to a resistive exercise intervention with and without superimposed whole-body vibrations

Whole‐body vibration (WBV) training is commonly practiced and may enhance peripheral blood flow. Here, we investigated muscle morphology and acute microcirculatory responses before and after a 6‐week resistive exercise training intervention without (RE) or with (RVE) simultaneous whole‐body vibrations (20 Hz, 6 mm peak‐to‐peak amplitude) in 26 healthy men in a randomized, controlled parallel‐design study. Total haemoglobin (tHb) and tissue oxygenation index (TOI) were measured in gastrocnemius muscle (GM) with near‐infrared spectroscopy (NIRS). Whole‐body oxygen consumption (VO2) was measured via spirometry, and skeletal muscle morphology was determined in soleus (SOL) muscle biopsies. Our data reveal that exercise‐induced muscle deoxygenation both before and after 6 weeks training was similar in RE and RVE (P = 0·76), although VO2 was 20% higher in the RVE group (P<0·001). The RVE group showed a 14%‐point increase in reactive hyperaemia (P = 0·007) and a 27% increase in blood volume (P<0·01) in GM after 6 weeks of training. The number of capillaries around fibres was increased by 15% after 6 weeks training in both groups (P<0·001) with no specific effect of superimposed WBV (P = 0·61). Neither of the training regimens induced fibre hypertrophy in SOL. The present findings suggest an increased blood volume and vasodilator response in GM as an adaptation to long‐term RVE, which was not observed after RE alone. We conclude that RVE training enhances vasodilation of small arterioles and possibly capillaries. This effect might be advantageous for muscle thermoregulation and the delivery of oxygen and nutrients to exercising muscle and removal of carbon dioxide and metabolites.