Daily physical activity and physical fitness from adolescence to adulthood: A longitudinal study

The stability of physical fitness and physical activity in Flemish males fr om 18 to 40 years of age was investigated. In addition, effects of a consis tently low-activity or high-activity level during the same age period on ph ysical fitness were studied. The sample consisted of males who were followe d longitudinally from age 13 to age 18 years, and were remeasured at the ag es of 30, 35, and 40 years. Complete data about physical fitness and physic al activity between 13 and 40 years were available for 130 subjects. Stabil ity was measured using Pearson autocorrelations and simplex models. Multiva riate analysis of variance (MANOVA) for repeated measurements was used to l ook for the effects of activity level on physical fitness. Simplex models s howed higher stability coefficients than Pearson correlations, and stabilit y of physical fitness was higher than stability of physical activity. Physi cal fitness showed the highest stability in flexibility (r = 0.91 between 1 8 and 30 years, r = 0.96 for both the 30-35 and 35-40 ages intervals), whil e physical activity showed the highest stability during work (r between 0.7 0 and 0.98 for the Ei-year intervals). Results from MANOVA indicated that f or some fitness characteristics the high-active subjects were more fit than their low-active peers. Stability of physical activity was higher than ass umed and, therefore, it is a useful and independent indicator for further r esearch. Although possible confounding factors are present (e.g., heredity) , a higher level of physical activity during work and leisure time on a reg ular basis benefits physical fitness considerably. (C) 2000 Wiley-Liss, Inc .