Abstract
OBJECTIVES: The aim of this systematic review was to summarize the evidence on the associations between the sleep duration or sleep quality and cardiorespiratory and muscular fitness in children and adolescents aged 6-19 years. MATERIAL AND METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta- analyses (PRISMA) and was registered with the international prospective register of systematic reviews PROSPERO network. Three databases (PubMed, SPORTDiscus and Science Direct) were searched until October 2019 for scientific articles concerning sleep duration, sleep quality and physical fitness. RESULTS: Six articles, including 5797 participants, from 11 different countries, were included in the current systematic review. CONCLUSION: Longer periods of sleep and better sleep quality were associated with higher levels of physical fitness.