title: High-volume sports club participation and autonomic nervous system activity in children.
abstract: BACKGROUND
  Sixty minutes of daily moderate-to-vigorous physical activity (PA) are recommended for children. This study investigated the additional impact of high-volume sports club participation on the autonomic nervous system in active children, while controlling for acute effects of short-term PA.
  
  
  METHODS
  Forty-nine children (29 females) aged 10-13 years were investigated. Sports club participation was assessed with a validated questionnaire. Short-term PA and night-time autonomic tone (spectral power and nonlinear analysis of heart rate variability) were measured with an ambulatory device (Actiheart(®) ). Children were dichotomized into two groups, based on their individual weekly time spent in a sports club: low-volume group < 180 min/week (N = 26) and high-volume group ≥ 180 min/week (N = 23).
  
  
  RESULTS
  Children in the high-volume group exhibited higher indices of vagal tone compared with the children in the low-volume group. Short-term moderate PA had a significant impact on the night course of autonomic activity. Boys showed a linear increase in vagal activity over the night course in relation to volumes of short-term moderate PA of the previous day. A similar but nonsignificant trend was observed for girls.
  
  
  CONCLUSIONS
  In active children, higher volumes of sports club participation have an additional benefit on indices of autonomic tone.
authors.affiliation: Division of Cardiovascular Prevention, Rehabilitation and Sports Cardiology, University Clinic for Cardiology, Inselspital, University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Radtke
authors.forename: Kerstin
authors.initials: K
authors.lastname: Khattab
authors.forename: Nicolas
authors.initials: N
authors.lastname: Brugger
authors.forename: Prisca
authors.initials: P
authors.lastname: Eser
authors.forename: Hugo
authors.initials: H
authors.lastname: Saner
authors.forename: Matthias
authors.initials: M
authors.lastname: Wilhelm
mesh_terms: D000293:Adolescent; D001341:Autonomic Nervous System / Q000502:physiology*; D002648:Child; D002940:Circadian Rhythm / Q000502:physiology; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D013177:Sports / Q000502:physiology*
keywords: Accelerometer; autonomic nervous system; heart rate variability; schoolchildren