Effectiveness of High-Intensity Interval Training on cardiorespiratory fitness and body composition in preadolescents: A systematic review

Objective: The aim of this study is to review the published literature on the effectiveness of high-intensity interval training (HIIT) interventions on cardiorespiratory fitness and body composition in preadolescents. Method: The databases used in the study were: PubMed, SPORTDiscus and Google Scholar. We included studies published from 2005 to 2016. The included studies consider: children, examined health-related fitness outcomes, involved an intervention of ≥2 weeks, included a control or moderate intensity comparison group, or both, and prescribed high intensity activity. Results: HIIT was associated with improvements in cardiorespiratory fitness in 9 of the 10 studies. In body composition, the improvements were less evident; on body mass index (2 studies), skinfolds (1 study) and on the percentage of body fat (4 studies). Conclusion: HIIT in preadolescents could be an efficient approach for improving cardiorespiratory fitness; nevertheless, its effect on body composition is still unclear.