Familial Resemblance In Physical Fitness

Abstract

Given the positive relationship between health related physical fitness and health status, insight in determinants of physical fitness might be useful for intervention and/ or health promotion campaigns. These determinants can be influenced by genetic and non-genetic relationships between family members. PURPOSE To quantify familial resemblance in physical fitness components. METHODS 148 fathers (47y ± 0.7) of the “Leuven Longitudinal Study on Lifestyle, Fitness and Health”, 103 mothers (44.4y ± 2.6), 60 sons (17.3y ± 1.8) and 45 daughters (17. 1y ± 2.2) performed physical fitness tests to quantify muscular strength (isometric, explosive, functional and trunk), maximal aerobic performance, speed of limb movement, flexibility and balance. Pearson product moment correlations were calculated between all family members to estimate familial resemblance in physical fitness characteristics. RESULTS Largest correlations between genetically related family members were found for isometric strength (0.24–0.70), maximal aerobic performance (0.16–0.42) and flexibility (0.14–0.37). High father-mother-correlations were found for isometric strength (0.48), maximal aerobic performance (0.42) and speed of limb movement (0.28). For trunk strength significant parent-son correlations were observed (0.31–0.34) and the spousal correlation was 0.22, although it was not significant. Family members' scores for balance and explosive strength did not correlate significantly. CONCLUSIONS As first degree family members share on average 50% of their genetic material, correlations found in this study for isometric strength, maximal aerobic performance and flexibility suggest a component of genetic transmission. However, as the spousal correlations for isometric strength, maximal aerobic performance and speed of limb movement are quite high (0.28–0.48), assortative mating and/or shared environmental factors are presumably also causing part of the variance of these variables. No clear patterns can be derived from the familial correlations in balance and explosive strength, suggesting larger individual environmental influences. Supported: The Flemish Policy Research Center Sport, Physical Activity and Health is supported by the Flemish Government.