Effects of aerobic exercise and resistance exercise on physical indexes and cardiovascular risk factors in obese and overweight school-age children: A systematic review and meta-analysis.

Childhood obesity often carries forward into adulthood, and physical exercise is widely promoted as a way to help manage weight and cardiovascular risk in overweight or obese school-age children. This review pooled results from randomized controlled trials comparing aerobic and resistance exercise programs against control conditions in children aged 6 to 12, looking at body mass index, body fat percentage, fitness, and blood lipid and cholesterol markers. Across 13 trials involving just over 500 children, exercise was associated with improvements in body mass index, body fat percentage, aerobic fitness, triglycerides, LDL cholesterol, and total cholesterol, but not in HDL cholesterol, which showed no statistically significant change. A key limitation is that only two of the 13 trials used resistance exercise, with the rest focused on aerobic exercise, so the authors could not meaningfully compare the two exercise types against each other, and insulin-related outcomes could not be analyzed at all due to insufficient data.

If you're a parent wondering whether exercise programs can help an overweight or obese child, this review looked at that question by combining results from 13 smaller studies involving just over 500 school-age children between 6 and 12 years old. The studies tested aerobic exercise, like running or cycling, and resistance exercise, like strength training, against no-exercise comparison groups. Overall, children who exercised tended to show improvements in body mass index, body fat percentage, fitness levels, and several blood fat and cholesterol measures, though one type of cholesterol, called HDL, showed no clear change.

It's encouraging to see consistent patterns across several measures, but there's an important catch: almost all the included studies looked at aerobic exercise rather than resistance training, so this research can't really tell us whether one type of exercise works better than the other, or how resistance exercise alone performs, since so few trials tested it. Researchers also couldn't examine effects on insulin because not enough studies measured it.

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

This meta-analysis included 13 randomized controlled trials totaling 504 participants, comparing aerobic and/or resistance exercise against control conditions in overweight or obese children aged 6 to 12. Pooled between-group analyses found statistically significant improvements favoring exercise for body mass index (mean difference -0.66, p<0.00001), body fat percentage (mean difference -1.29, p=0.02), VO2peak (standardized mean difference 1.25, p=0.001), triglycerides (standardized mean difference -1.14, p=0.005), LDL (standardized mean difference -1.38, p=0.003), and total cholesterol (standardized mean difference -0.77, p=0.002).

HDL showed no statistically significant difference (standardized mean difference 0.13, p=0.27). A major constraint on interpretation is the imbalance in study types: only two trials examined resistance exercise compared with twelve on aerobic exercise, precluding any comparison of exercise modality effects, and the review does not report on risk of bias or heterogeneity assessment for the pooled estimates. Insulin and insulin resistance outcomes could not be analyzed due to insufficient reporting across trials.

Clinicians should view these findings as association-based evidence from a modest body of pediatric trials rather than a robust head-to-head comparison of aerobic versus resistance training.