Better Health-Related Fitness in Youth: Implications for Public Health Guidelines.

Public health guidelines for physical activity (PA) behaviors are being updated with 2018 as a proposed release date. Currently, ≥60 minutes of daily PA are recommended for youth. Thus, the purpose of this study was to investigate the association between reported days of aerobic PA and health-related fitness (HRF). Participants included 4448 students in grades 6-8. Self-reported days of ≥60 minutes of aerobic PA was obtained. HRF was assessed with FitnessGram. Discriminant analysis indicated that weekly days of aerobic PA related to HRF. Adolescents who participated in ≥5 days of weekly aerobic PA generally had better fitness results than those with ≤4 days. Chi-square analyses indicated the highest percentages of adolescents in the FitnessGram Healthy Fitness Zone™ (HFZ) for each test item were those with ≥5 days of aerobic PA. These findings provided initial support that the impact of aerobic PA on HRF plateaus at 5 days per week. Thus, adolescents may be able to improve HRF even if they do not meet the currently recommended guidelines for daily PA.