title: Relaxation effects in humans of underwater exercise of moderate intensity.
abstract: In this study we investigated the effects of underwater exercise in warm water (34 degrees C) on physiological and psychological relaxation. Eight healthy young men (aged 20-26 years) volunteered for the experiment. The experiment consisted of the following three successive segments: a pre-exercise period of 20 min, during which the subjects rested in a semi-supine posture with their eyes closed for the final 10 min; an underwater exercise period of approximately 60 min, during which the subjects performed gymnastic exercises or aerobic dancing with occasional movements or jumping; a post-exercise recovery of 20 min, which was similar to the pre-exercise rest period. We compared the relative power values (power %) of the electroencephalogram alpha bands (8-13 Hz) and profile of moods states (POMS) before and after the underwater exercise. We also estimated the percentage of maximal heart rate (%HRmax) throughout the experiment to ascertain the intensity of the underwater exercise. The results of %HRmax indicated that the intensity of underwater exercises practised in the experiments ranged from low to moderate. The power % of EEG alpha bands had increased significantly after the underwater exercise compared with the pre-exercise rest (P<0.05). From the POMS results, we observed that positive mood (vigour) increased and negative mood (tension and anxiety, depression and dejection) decreased significantly after the underwater exercise (P<0.05). This study found that the subjects showed increased physiological and psychological indices of relaxation after underwater exercise.
authors.affiliation: Department of Health and Physical Education and Research, Faculty of Education, Hokkaido University, Sapporo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Oda
authors.forename: T
authors.initials: T
authors.lastname: Matsumoto
authors.forename: K
authors.initials: K
authors.lastname: Nakagawa
authors.forename: K
authors.initials: K
authors.lastname: Moriya
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology; D004562:Electrocardiography; D004569:Electroencephalography; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D012064:Relaxation Therapy