title: Microcirculation of skeletal muscle adapts differently to a resistive exercise intervention with and without superimposed whole-body vibrations.
abstract: 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.
authors.affiliation: German Aerospace Center, Institute of Aerospace Medicine and Space Physiology, Cologne, Germany.|Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Cologne, Germany.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Beijer
authors.affiliation: School of Healthcare Science, Manchester Metropolitan University, Manchester, UK.
authors.forename: Hans
authors.initials: H
authors.lastname: Degens
authors.affiliation: German Aerospace Center, Institute of Aerospace Medicine and Space Physiology, Cologne, Germany.|Space Medicine Office, Directorate of Human Spaceflight and Operations (D/HSO) European Space Agency, European Astronaut Centre, Cologne, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Weber
authors.affiliation: German Aerospace Center, Institute of Aerospace Medicine and Space Physiology, Cologne, Germany.|German Sport University Cologne, Institute of Training Science and Sports Informatics, Cologne, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Rosenberger
authors.affiliation: Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Cologne, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Gehlert
authors.affiliation: German Aerospace Center, Institute of Aerospace Medicine and Space Physiology, Cologne, Germany.
authors.forename: Frankyn
authors.initials: F
authors.lastname: Herrera
authors.affiliation: RheinAhrCampus, Remagen, University of Applied Sciences Koblenz, Koblenz, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kohl-Bareis
authors.affiliation: German Aerospace Center, Institute of Aerospace Medicine and Space Physiology, Cologne, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Zange
authors.affiliation: Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Cologne, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Bloch
authors.affiliation: German Aerospace Center, Institute of Aerospace Medicine and Space Physiology, Cologne, Germany.|School of Healthcare Science, Manchester Metropolitan University, Manchester, UK.
authors.forename: Jörn
authors.initials: J
authors.lastname: Rittweger
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D002196:Capillaries / Q000502:physiology*; D003131:Combined Modality Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D018482:Muscle, Skeletal / Q000098:blood supply / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods*; D055070:Resistance Training / Q000379:methods*; D016896:Treatment Outcome; D014732:Vibration
keywords: capillarization; muscle oxygenation; resistance exercise; whole-body vibration