High-Intensity Interval Training and Cardiometabolic Risk Factors in Children: A Meta-analysis

High-intensity interval training (HIIT) has been widely used to prevent and treat cardiovascular risk factors in adolescents and adults; nevertheless, the available evidence in children is scarce. To synthesize evidence regarding the effectiveness of HIIT interventions on improving cardiovascular risk factors and cardiorespiratory fitness (CRF) in children from 5 to 12 years old. We searched 5 databases, Medline, Embase, SPORTDiscus, the Cochrane Library, and Web of Science. Randomized controlled trials (RCTs) evaluating the effectiveness of HIIT interventions on cardiometabolic risk factors and CRF in children were included. Meta-analyses were conducted to determine the effect of HIIT on body composition, cardiometabolic and CRF variables in comparison with nontraining control groups. A total of 11 RCTs and 512 participants were included. The results of the meta-analysis revealed a significant improvement in peak oxygen uptake (standardized mean difference [SMD] = 0.70, 95% confidence interval [CI] = 0.28 to 1.12; = 0.001], in total cholesterol [SMD = -1.09, 95% CI = -1.88 to -0.30; = 0.007], in low-density lipoprotein cholesterol [SMD = -1.28, 95% CI = -2.34 to -0.23; = 0.017] and triglycerides [SMD = -0.71, 95% CI = -1.15 to -0.28; = 0.001) levels. Because of the small number of available RCTs, it was not possible to conduct a subgroup analysis or a linear meta-regression analysis. HIIT is a feasible and time-efficient approach for improving CRF, total cholesterol, low-density lipoprotein cholesterol, and triglycerides levels in children.