Physical fitness, body fatness, and physical activity: The Amsterdam Growth and Health Study.

The purpose of this study was to examine sex-specific longitudinal relationships between physical fitness (cardiopulmonary and neuromotor fitness) and body fatness (sum of skinfolds) and to examine the influence of physical activity (weighted activity score) on these relationships. The data were obtained from the Amsterdam Growth and Health Study (AGHS), an observational longitudinal study of 98 females and 83 males, with six repeated measurements over a period from 13 to 27 years of age. The longitudinal relationship between body fatness and physical fitness was analyzed using generalized estimating equations (GEE). For each of the eight fitness items used as outcome variables, standardized regression coefficients were calculated for the relationships with body fatness and for the relationships with physical activity with and without correcting for height and weight. In all analyses, body fatness was inversely related to running speed, standing high jump, leg lift speed, and maximal oxygen uptake. Physical activity was positively related to leg lift speed and maximal oxygen uptake, and only in females to the standing high jump. Thus, body fatness is inversely related to most fitness items, while physical activity is positively related to only several fitness items. Further, body fatness and physical activity are independently related to physical fitness. Am. J. Hum. Biol. 12:593-599, 2000. Copyright 2000 Wiley-Liss, Inc.