Absolute and relative intensity physical activity of children with healthy and low levels of cardiorespiratory fitness
Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Introduction
Accelerometer-derived outcomes describing physical activity (PA) volume and intensity distribution relative to a person’s maximal capacity have provided insight into associations with health in adults. Little is known, however, about how the relative intensity of children’s PA volume and intensity distribution relates to health or fitness. To address this, we examined associations between children’s absolute and relative PA volume and intensity distribution with cardiorespiratory fitness (CRF), and differences in these PA outcomes for children stratified by CRF level.
Materials and Methods
In 9–10-year-old children (N=235) PA was assessed using wrist accelerometers for up to 7-days and CRF estimated from the 20-m multistage shuttle run test (20mSRT). Children were classified as Healthy or Low CRF. Absolute PA outcomes were PA volume (average acceleration; AvAcc abs ) and intensity distribution (intensity gradient; IG abs ). Equivalent relative PA outcomes were generated (AvAcc rel and IG rel ) using maximum acceleration values derived from the 20mSRT.
Results
Absolute, but not relative standardised PA outcomes were positively associated with CRF (AvAcc abs Std β =0.21, p =0.02; IG abs Std β =0.21, p =0.03). Absolute standardised PA outcomes were significantly higher among Healthy CRF children (AvAcc abs Std β =0.40, p =0.007; IG abs Std β =0.46, p =0.008), but there were no significant differences between Healthy and Low CRF groups for relative PA outcomes.
Conclusions
Children were similarly active relative to their physiological capacity, despite children with Healthy CRF being more active in absolute terms. Future studies should seek to better understand the influence of relative PA on CRF among diverse child populations who differ on a range of physical, physiological and demographic characteristics.
