Research shows resistance training may improve body weight in young people.
Researchers from the Universities of Edinburgh and Dundee in Scotland looked at numerous studies on the effects of resistance training on people aged eight to 16.
They found that exercises where the muscles contract reduced children’s body fat percentage.
Published in the journal Sports Medicine, this is the most extensive review on this topic so far.
The researchers analysed 18 different studies from eight different countries, including Australia, the US and Japan.
The meta-analysis investigated eight outcomes related to weight status: body mass, BMI body fat, fat-free mass, fat mass, lean mass, skinfolds and waist circumference.
It found that “resistance training has a positive effect on body fat percentage and skinfolds in youth”.
Strangely, the study also found that resistance training had no significant effect on the other six outcomes.
The researchers speculate that strength training helps reduce body fat in young people by increasing skeletal muscle mass, which in turn increases basal metabolic rate. That is, kids build more muscle and the metabolism ramps up to deal with it.
However, this result might also be explained by the simple act of taking up an exercise activity, and the resultant overall energy expenditure, rather than the specific strength training intervention itself.
The biological changes of adolescence also might have played a role.
“Treatment, and more importantly, prevention, of child obesity is a growing concern,” said lead author Helen Collins.
“Our findings highlight the need for more robust research into the role strength-based exercises can play in helping everyone make healthy life choices and be more physically active.”
Although these results are positive, the authors note that it does represent only a small body of published work.
Further studies will be needed to pinpoint the more precise mechanisms of resistance training’s effect on young people’s weight loss.
Collins, H. et al. (2018.) ‘The effect of resistance training interventions on weight status in youth: a meta-analysis.’ Sports Medicine. 20184:41.
Published: 20 August 2018 https://doi.org/10.1186/s40798-018-0154-z