ANGIOGENIC STIMULI OF RESISTANCE EXERCISE AND SUPERIMPOSED WHOLE-BODY VIBRATIONS

Abstract

OBJECTIVES: Whole-body vibration (WBV) training has become a popular training mode in the past few years and is nowadays applied in various fields like sports, rehabilitation and preventive medicine. WBV training has been shown to improve peripheral perfusion and may elicit muscle deoxygenation. We hypothesized that the superposition of WBV to resistance exercise would add a pro-angiogenic stimulus to the training and we aimed to find a novel training mode that concurrently induces muscle hypertrophy and capillary growth in order to improve muscle performance. METHODS: A six-week training study including 26 healthy males was conducted in a randomized two-group parallel design, in which one group performed resistance exercise (RE) and the other group resistance exercise with superimposed whole-body vibrations (RVE). Subjects trained 2-3 times per week, concluding 16 training sessions. The training consisted of squatting exercise and calf raises performed with heavy loads that were set at 80% of the one-repetition maximum. During the initial and final exercise sessions of the 6-week intervention, measurements were performed at rest, during and acutely after exercise. Blood volume and tissue oxygenation were determined in gastrocnemius via near infrared spectroscopy. Angiogenic markers (matrix metalloproteinase -2 and -9, vascular endothelial growth factor (VEGF) and endostatin) were measured in serum via ELISA and the proliferative effect upon human umbilical vein endothelial cells was determined in vitro. Finally, long-term effects of the trainings on muscle morphology were determined in soleus biopsies. RESULTS: Our data are to our knowledge the first to describe transient increases of circulating angiogenic markers after resistance exercise. VEGF levels were acutely higher in the RE group, which supposedly provoked increased proliferation of endothelial cells in vitro. Furthermore, acute increases in circulating endostatin were higher in the RE group after the six-week training intervention. These effects were elusive in the RVE group. Despite differences in acute VEGF levels, capillary growth in soleus muscle was not different between groups. However, total blood volume and exercise hyperemia was increased after six weeks of RVE training. CONCLUSIONS: Our data indicate the pro-angiogenic stimulus of RE is not increased by superimposing WBV to the training. While structural adaptations in muscle tissue were similar in both groups, regular RVE training seems to influence the functional state of small arterioles and potentially capillaries, enhancing muscle perfusion and post-exercise hyperemia.