This study investigated the potential impact of a motor skill proficiency barrier on measures of cardiorespiratory (CRF) and musculoskeletal (MSF) fitness in youth. A sample of 241 youth (114 girls) aged 10 - 18 years, completed the Motor Competence Assessment battery with composite scores indexed according to age- and gender-adjusted percentile scores. Motor competence (MC) levels were categorized as low (≤ 25...