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

CONTEXT: 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. OBJECTIVE: 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. DATA SOURCES: We searched 5 databases, Medline, Embase, SPORTDiscus, the Cochrane Library, and Web of Science. STUDY SELECTION: Randomized controlled trials (RCTs) evaluating the effectiveness of HIIT interventions on cardiometabolic risk factors and CRF in children were included. DATA EXTRACTION: Meta-analyses were conducted to determine the effect of HIIT on body composition, cardiometabolic and CRF variables in comparison with nontraining control groups. RESULTS: 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; P = 0.001], in total cholesterol [SMD = -1.09, 95% CI = -1.88 to -0.30; P = 0.007], in low-density lipoprotein cholesterol [SMD = -1.28, 95% CI = -2.34 to -0.23; P = 0.017] and triglycerides [SMD = -0.71, 95% CI = -1.15 to -0.28; P = 0.001) levels. LIMITATIONS: Because of the small number of available RCTs, it was not possible to conduct a subgroup analysis or a linear meta-regression analysis. CONCLUSIONS: HIIT is a feasible and time-efficient approach for improving CRF, total cholesterol, low-density lipoprotein cholesterol, and triglycerides levels in children.

The effectiveness of high-intensity interval training on body composition, cardiorespiratory fitness, and cardiovascular risk factors in children: A protocol for a systematic review.

BACKGROUND: No previous systematic review has examined the effect of high-intensity interval training (HIIT) interventions on body composition, cardiometabolic risk factors and cardiorespiratory fitness (CRF) in healthy schoolchildren from 5 to 12 years old. METHODS: This study will be conducted by following the guideline of the preferred reporting items for systematic review and meta-analysis protocols. An electronic search in MEDLINE (via PubMed), EMBASE (via Scopus), SPORTDiscus, Cochrane Library and Web of Science databases of all dates from inception will be conducted. We will include randomized controlled trials aimed to assess the effectiveness of HIIT to improve cardiometabolic risk factors, body composition, and CRF in children. Two authors will perform the study selection and data collection; disagreements will be solved by a third reviewer. The methodological quality of studies will be assessed by the Cochrane Collaboration's tool for assessing risk of bias (RoB2). Data analysis and synthesis will be performed by Comprehensive Meta-analysis Software and StataSE software, version 15. CONCLUSION: The results should be disseminated through publication in a peer-reviewed journal. Since the data used in systematic reviews of this type will be extracted exclusively from published studies, approval form and ethics committee will not be required.