The effects of different exercise intensities on body composition and cardiovascular risk indicators in children with metabolic syndrome: a RCT network meta-analysis.

Background: Metabolic Syndrome in children, marked by obesity, insulin resistance, hyperglycemia, hypertension, and dyslipidemia, is rising globally, affecting body composition, cardiac function, and long-term health. Traditional treatments face challenges, especially for children. Exercise interventions, including low, medium, high, and extremely high intensities, have been studied for their benefits in improving body weight, reducing fat, and enhancing fitness. This paper evaluates the effects of these exercise intensities on body composition and cardiac function in children with Metabolic Syndrome, offering new insights for clinical treatment.

Methods: Six databases, including Web of Science, PubMed, EBSCO, Embase, China National Knowledge Infrastructure (CNKI) and Cochrane, were systematically searched (between 2008 and 2025), and 35 randomized controlled trials with a total of 2299 pediatric Metabolic Syndrome patients(Age:3.69 to 16.7). The outcome indicators were relevant indicators for evaluating body composition and cardiac function. All eligible studies were assessed for risk of bias (ROB 2.0) according to the Cochrane 5.1 version. Net meta-analysis was performed using Stata 18.0 to assess the relative effectiveness of each intervention and to test the consistency of direct and indirect evidence.

Results: Extremely high-intensity exercise (≥ 94% HRmax) significantly reduced Body Mass Index (SMD = -0.80, 95% CI [-1.54, -0.06], p < 0.00001), Body Fat Percentage (SMD = -2.71, 95% CI [-4.29, -1.13], p = 0.11), and improved Glycometabolism (SMD = -2.06, 95% CI [-4.20, 0.08], p < 0.00001) and Maximum Oxygen Uptake (SMD = 1.83, 95% CI [0.02, 3.64]). It also enhanced cardiovascular health (SMD = -5.83, 95% CI [-8.23, -3.43], p < 0.00001). Medium (64-76% HRmax) and high-intensity training (77-93% HRmax) showed some benefits but were not statistically significant. Low-intensity training (50-63% HRmax), while less effective, remains clinically valuable for safety and adaptive interventions in specialized groups.

Conclusion: This study found that extremely high-intensity exercise was most effective in improving BMI, body fat percentage, glucometabolic function, and cardiac health in children with Metabolic Syndrome, especially in the short term. Low-intensity exercise, though less effective, is still useful for improving metabolic health and increasing participation, particularly for children with lower fitness levels.