High‐volume sports club participation and autonomic nervous system activity in children

Abstract

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. Forty-nine children (29 females) aged 10-13years 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 <180min/week (N=26) and high-volume group ≥180min/week (N=23). 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. In active children, higher volumes of sports club participation have an additional benefit on indices of autonomic tone.