Effects of school-based concurrent training on body composition and cardiorespiratory fitness in obese children in a randomized controlled trial.

Childhood obesity raises long-term risks for heart and metabolic disease, so schools are often considered a practical setting for exercise interventions, though which combination of activities works best remains unclear. This small trial tested two eight-week programs in obese children, each pairing short sprint interval training with either aerobic exercise or strength training, against a non-exercise control group over two sessions a week. Both exercise groups showed reductions in body mass index and fat mass and improvements in cardiorespiratory fitness compared with the control group, and no adverse events were reported. The strength-based combination produced a larger fitness gain than the aerobic combination, though the trial did not directly establish whether one program was superior overall for body composition.

With only thirty children across three groups, these results are an early signal rather than firm proof of which approach works best.

If you've wondered whether short bursts of exercise at school could help children who are obese, this small trial offers some early answers. Thirty obese children, aged around ten, were split into three groups: one did brief sprint intervals combined with aerobic exercise, another combined sprint intervals with strength training, and a third group did no structured exercise at all, twice a week for eight weeks. Both exercise groups saw improvements compared to the no-exercise group, including reductions in body mass index and body fat, along with better cardiorespiratory fitness.

The strength-training combination led to a bigger improvement in fitness than the aerobic combination, though the study can't tell us whether one combination was clearly better overall for reducing body fat. This is reassuring in a small way, but with only ten children per group, it's a modest study. No safety problems were reported, but larger studies would be needed before drawing firm conclusions about which exercise combination works best for obese children.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

This trial addresses a practical question in paediatric obesity management: when combining sprint interval training with a second exercise mode in a school setting, does pairing it with aerobic work or resistance work matter for outcomes clinicians care about, body composition and cardiorespiratory fitness. Thirty obese children (mean age 10.1 years) were randomised to sprint interval plus aerobic training (CT1, n=10), sprint interval plus strength training (CT2, n=10), or non-exercise control (n=10), with two sessions weekly for eight weeks. Both intervention groups showed statistically significant reductions in BMI and fat mass and improvements in VO2max versus control.

The CT2 group had a significantly greater VO2max increase than CT1 (6.1 vs 3.1 mL/kg/min, p<0.01), while visceral adipose tissue reduction was specific to CT1 and waist circumference reduction specific to CT2, with no significant between-group differences reported for these two measures. This pattern suggests some outcome-specific effects worth noting, but the trial was not powered to establish superiority of one combined protocol over the other for body composition overall. The very small per-group sample size (n=10) and short eight-week duration limit generalisability, and no adverse events were reported, though safety was not the primary focus of the trial.