Students with excess weight obtain lower physical fitness test scores in physical education than normal weight pairs: myth or reality?

The aim of this study was to investigate through a systematic review the possible influence of excess weight on physical fitness test results carried out by adolescents in physical education classes, taking into account potential confounders. Fourteen studies were identified in four databases (PubMed, SportDiscus, Web of Science, and SCOPUS) from January 2000 through to April 2018. Titles and abstracts were reviewed to determine whether the studies met the inclusion criteria. The quality of the reporting of the measures was assessed using a tailored list. Four studies were longitudinal and nine used a cross-sectional design. Overweight and obese youth were associated with lower cardiorespiratory fitness and motor fitness than their normal weight peers in 10 and 7 studies, respectively. Likewise, overweight and obesity impair performance in muscular fitness tests where body weight acted as ballast (i.e. standing long jump or abdominal tests), while the relationship with regard to other muscular fitness tests (i.e. handgrip) and flexibility (sit and reach) has been less studied and the results show no association. Conclusively, in adolescents, excess weight negatively influences cardiorespiratory fitness, motor fitness, and muscular tests that involve mobilizing body weight.