title: EMG and heart rate responses decline within 5 days of daily whole-body vibration training with squatting.
abstract: 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.
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany; Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Rosenberger
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany; Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany.
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Liphardt
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany; Medical Faculty, University of Cologne, Cologne, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Bargmann
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Müller
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.
authors.forename: Luis
authors.initials: L
authors.lastname: Beck
authors.affiliation: Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Mester
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany; Medical Faculty, University of Cologne, Cologne, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Zange
mesh_terms: D000328:Adult; D004576:Electromyography; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology; D014732:Vibration; D055815:Young Adult
chemical_list: D019344:Lactic Acid