Energy Costs of Physical Activities in Children and Adolescents

TLDR

The study aimed to quantify the energy expenditure and metabolic equivalents of common activities in children and adolescents, and to determine when these values converge with adult levels. A descriptive study of 295 volunteers aged 8–18 performed 18 activities in random order while EE was continuously measured with a portable metabolic system, with pubertal stage estimated by questionnaire. Children’s resting and exercise EE per kilogram were higher than adults and declined with age and pubertal stage; age‑ and puberty‑adjusted EE values were lower than compendium METs for sedentary/moderate activities but comparable for high‑intensity ones, indicating that adult‑based MET definitions are inadequate until Tanner Stage 5, though the activity‑to‑resting EE ratio remains similar to compendium estimates.

Abstract

The primary aim was to determine the energy expenditure (EE: kcal.kg(-1).h(-1)) in terms of caloric cost and metabolic equivalents of activities commonly performed by children and adolescents. Secondary aims were to determine at what age and pubertal developmental stage values approach those of adults.In this descriptive study, 295 volunteer youth 8-18 yr of age completed 18 common physical activities (including rest) while EE was measured continuously with a portable metabolic system. Three sets of activities were assigned in random order for each subject. Activities ranged from television viewing and video game play to running and rope skipping. Pubertal development was estimated from a self-report questionnaire.At rest, VO(2) and EE were highest in the youngest children and decreased with advancing age and higher pubertal stage in both genders. The age-adjusted and puberty-adjusted energy expenditure values were generally lower than the compendium MET values for sedentary and moderate activities but were more varied for high-intensity activities. However, the ratio of activity EE to REE was comparable in children and adults.Energy expenditure per kilogram of body mass at rest or during exercise is greater in children than adults and varies with pubertal status, thus using the definition of a MET in the compendium of physical activities without adjustment is inadequate for energy estimation in children, until a child reaches Tanner Stage 5. However, the ratio of activity EE to resting EE in children appears to be similar or slightly less than in the compendium, suggesting that the compendium MET increments used with our adjusted EE values more closely approximate the true EE of activities in children than present adult norms.