Children and adolescents who are physically fit tend to maintain fitness levels into adulthood Existing research indicates that physical fitness during youth is beneficial for health during adulthood. These benefits include improved body composition, healthier cardiometabolic profiles, and reduced risk of chronic disease. Because childhood and adolescent fitness influence subsequent adult health outcomes, it is important to investigate how fitness components track across the life course. This systematic literature review and meta-analysis examined the existing evidence to determine if physical fitness during childhood and/or adolescence is related to physical fitness in adulthood.
A literature search was conducted to identify studies that tracked physical fitness from childhood/adolescence into adulthood. Only longitudinal cohort studies that examined the relationship between physical fitness in childhood and/or adolescence (age 6–18) and physical fitness in adulthood (age 20 and over) were considered for inclusion in the review and meta-analysis. No limitations were placed on how physical fitness was measured. The search identified 21 studies that met these criteria; however, only 19 of the studies were included in the statistical meta-analysis due to data limitations. The selected studies involved a total of 6,197 participants (47% women). Individual study sample sizes ranged from 45 to 822. Most studies tracked fitness outcomes from adolescence to adulthood, although others examined fitness during childhood or both childhood and adolescence. On average, follow-up adult fitness assessments were completed 21 years after the initial assessment (in childhood/adolescence). A series of meta-analyses were conducted that combined the statistical findings of studies that examined the same fitness parameters. Meta-analyses were conducted for cardiorespiratory fitness, muscular strength, muscular endurance, and flexibility.
Cardiorespiratory fitness, muscular strength, and muscular endurance showed moderate tracking from childhood and/or adolescence into adulthood, indicating that these aspects of physical fitness remain somewhat consistent over the life course. These results did not differ based on gender, fitness assessment method, or length of follow-up. Flexibility showed high tracking from childhood and/or adolescence to adulthood, indicating that flexibility tends to remain highly stable across the life course. The length of follow-up was found to influence this association, with stronger relationships detected at longer follow-up times.
Overall results indicate that physical fitness, as measured by cardiorespiratory fitness, muscular strength, and muscular endurance, tends to stay relatively consistent from childhood or adolescence into adulthood. Flexibility in childhood and adolescence was more strongly linked to flexibility in adulthood, which may be partly explained by genetic factors. These findings suggest that children and adolescents who exhibit physical fitness tend to maintain similar levels of physical fitness into adulthood. Findings underscore the importance of childhood and adolescence as potential key periods for developing physical fitness, which may encourage better physical health and fewer chronic diseases throughout adulthood. The meta-analysis identified associations linking physical fitness in youth to physical fitness in adulthood; findings do not establish a cause-and-effect relationship. Although the study did not examine nature’s role in physical fitness, research has shown that time in nature promotes increased physical activity and supports improved physical health outcomes for children and youth. Therefore, increasing children’s engagement with nature can support improved physical fitness, which, as this study suggests, is likely to be maintained through adulthood.
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