title: Changes in arousal level by differential exercise intensity.
abstract: OBJECTIVE
  The purpose of the present study was to investigate the influence of exercise intensity on arousal level.
  
  
  METHODS
  Twelve subjects (22-33 years) performed a S1-S2 reaction time task consisting of warning stimulus (S1) and imperative stimulus (S2) in a control condition, and again after low, medium, and high intensity pedaling exercises. During this task, contingent negative variation (CNV) and spontaneous electroencephalogram before S1 were measured as indicators for arousal level.
  
  
  RESULTS
  CNV amplitude after high intensity pedaling exercise was significantly smaller than after medium pedaling exercise. Compared to the control condition, relative power value of alpha waves increased after the high intensity exercise.
  
  
  CONCLUSIONS
  These results suggested that arousal level was reduced after high intensity exercise and reached a state near optimal level after medium intensity exercise. The findings also suggested that changes in CNV amplitude by differences in exercise intensity followed an inverted-U shaped dose response curve.
  
  
  CONCLUSIONS
  The present study supported the view that CNV amplitude and arousal level followed an inverted-U relationship. It is concluded that differences in exercise intensity influenced arousal level.
authors.affiliation: Doctoral Program in Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8574, Japan. kamijo@seiri.taiiku.tsukuba.ac.jp
authors.forename: Keita
authors.initials: K
authors.lastname: Kamijo
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nishihira
authors.forename: Arihiro
authors.initials: A
authors.lastname: Hatta
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kaneda
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kida
authors.forename: Takuro
authors.initials: T
authors.lastname: Higashiura
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kuroiwa
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001143:Arousal / Q000502:physiology*; D001642:Bicycling; D003265:Contingent Negative Variation; D018913:Event-Related Potentials, P300; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male