The purpose of this study was to examine the association between seasonal participation in recreational sports and its influence on physical fitness measures in children. A total of 44 children (20 boys and 24 girls) all in the fifth grade (11.2 +/- 0.3 yr) were tested for flexibility, upper body strength, upper body power, and lower body power. Activity questionnaires examined seasonal participation rates in recreational sports. Spearman rank correlations showed significant correlations between sport participation rates and performance on selected physical fitness tests (p range between 0.34 and 0.55). Subjects participating in recreational sport programs throughout the year (fall, winter, and spring) performed significantly better in tests of upper body strength, upper body power, and lower body power than subjects who did not participate in any sport or subjects who participated in only one sport. These findings suggest that regular participation in recreational sports throughout the year may be associated with higher levels of muscular strength and anaerobic power in children.