Are prepubertal children metabolically comparable to well-trained adult endurance athletes?

Abstract

It is well acknowledged that prepubertal children have smaller body dimensions and a poorer mechanical (movement) efficiency, and thus a lower work capacity than adults. However, the scientific evidence indicates that prepubertal children have a greater net contribution of energy derived from aerobic metabolism in exercising muscle and reduced susceptibility to muscular fatigue, which makes them metabolically comparable to well-trained adult endurance athletes. For example, the relative energy contribution from oxidative and non-oxidative (i.e. anaerobic) sources during moderate-to-intense exercise, the work output for a given anaerobic energy contribution and the rate of acceleration of aerobic metabolic machinery in response to submaximal exercise are similar between prepubertal children and well-trained adult endurance athletes. Similar conclusions can be drawn on the basis of experimental data derived from intra-muscular measurements such as type I fibre percentage, succinate dehydrogenase enzyme activity, mitochondrial volume density, post-exercise phosphocreatine re-synthesis rate and muscle by-product clearance rates (i.e. H+ ions). On a more practical level, prepubertal children also experience similar decrements in peak power output as well-trained adult endurance athletes during repeated maximal exercise bouts. Therefore, prepubertal children have a comparable relative oxidative contribution to well-trained adult endurance athletes, but a decrease in this relative contribution occurs from childhood through to early adulthood. In a clinical context, this understanding may prove central to the development of exercise-based strategies for the prevention and treatment of many metabolic diseases related to mitochondrial oxidative dysfunction (e.g. in obese, insulin-resistant and diabetic patients), which are often accompanied by muscular deconditioning during adolescence and adulthood.

Document Type

Journal Article

Date of Publication

2017

Location of the Work

New Zealand

Publication Title

Sports Medicine

Publisher

Springer International Publishing

School

School of Medical and Health Sciences / Centre for Exercise and Sports Science Research

RAS ID

25405

Comments

Ratel, S., & Blazevich, A. J. (2017). Are prepubertal children metabolically comparable to well-trained adult endurance athletes?. Sports Medicine, 47(8), 1477-1485. https://doi.org/10.1007/s40279-016-0671-1

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Link to publisher version (DOI)

10.1007/s40279-016-0671-1