Sex differences in fitness outcomes among minority youth after participation in a park-based after-school program

Purpose: This study aimed to describe sex differences in fitness outcomes after participation in Fit2Play, a park-based after-school health and wellness program. Methods: Youth who participated in Fit2Play for either 1, 2, or 3 school years between 2010 and 2016 (n = 2129, mean age 9.1 years, 52% Hispanic, 48% non-Hispanic black, 54% male) were tested via a comprehensive fitness battery at the beginning/end of the school year(s). Effects of length of Fit2Play participation on fitness outcomes were assessed via three-level repeated measures analysis stratified by sex and adjusted for child sociodemographics, weight category, area poverty, and year. Results: Significant improvements for boys and girls were found in the Progressive Aerobic Cardiovascular Endurance Run (P <.01 for girls, P <.001 for boys), 400 meter run tests (P <.001 for girls, P <.01 for boys), and push-ups (P <.01 for both), with dose-response trends for girls after up to 3 years of Fit2Play participation. From baseline to 1, 2, and 3 years of participation, girls demonstrated 8%, 14%, and 23% mean improvement in 400 meter run times versus 9%, 9%, and 17% for boys, respectively (P <.001 for all). Dose-response improvements were also found in girls for PACER scores and sit-ups. Conclusions: After-school physical activity programs can improve fitness in all youth, and particularly girls with increased years of participation. Further research should examine sex differences in the effects of park-/community-based programs to reduce sex disparities in fitness, particularly in light of the current youth obesity epidemic.