Problem: the practice of physical exercise in general or of a particular sport is a crucial factor in the day to day, regardless of the age. The World Health Organization in general suggests that children and young people between the ages of 5 and 17, perform at least 60 minutes of physical activity daily. Objective: to know the impact and effects of sport on children and adolescents under 18 years. Materials and methods: systematic review combined with a descriptive analysis of retrospective chronology of clinical trials collected between January 2009 to June 2019, developing a search for clinical trials with databases such as Ebsco, Scielo, Medline, Medscape, PubMed Central, EMBASE, Redalyc, DOAJ and OVID. Results: encompassing all types of sports that were studied in the present investigation: reduction in fat mass and increase in lean mass, increase in VO2max levels, better turnover, resistance and optimal levels in bone densitometry, optimal levels in BMI, adequate values ejection fraction, delay in the appearance of menarche, in women. Conclusions: when analyzing the results of the included studies, sufficient evidence was found to associate the practice of various sports with multifactorial and multisystemic benefits in children and adolescents.