What is the role of adherence to 24-hour movement guidelines in relation to physical fitness components among adolescents?

Background: Physical inactivity, excessive sedentary time, and lack of sleep time have been independently associated with lower health-related physical fitness. However, little is known about the combined association between 24-h movement guidelines (i.e., physical activity, recreational screen time, and sleep duration) and components of physical fitness.

Objective: The main aim was to examine the likelihood of having high/very high levels on different components of physical fitness based on meeting with 24-h movement guidelines.

Methods: In this cross-sectional study, 1276 Spanish youths (13.07 ± 0.86; 55.88% boys), aged 11-16 years, completed self-reported questionnaires on physical activity, recreational screen time, and sleep duration. Physical fitness components were assessed by 20-m shuttle-run test, standing long jump test, handgrip strength test, and 4 × 10-m shuttle-run test. Meeting 24-h movement guidelines was defined as: 9-11 h/day (children aged 5-13) or 8-10 h/day (adolescents aged 14-17) of sleep, ≤2 h/day of recreational screen time and at least 60 min/day of moderate-to-vigorous physical activity. The probability of having a high/very high score for each physical fitness components (i.e., ≥60th centile according to the normative cut-off points for European adolescents) in relation to adherence to 24-h movement guidelines was analyzed using a series of binary logistic regressions.

Results: Participants who met the three 24-h movement guidelines were more likely to have high/very high for cardiorespiratory fitness (OR = 3.31; 95% CI: 1.79, 6.14; p < 0.001), standing long jump (OR = 1.91; 95% CI: 1.06, 3.45; p = 0.031), muscular fitness (OR = 2.05; 95% CI: 1.09, 3.86; p = 0.048) and physical fitness (OR = 1.99; 95% CI: 1.08, 3.66; p = 0.012), but not for handgrip strength (OR = 1.15; 95% CI: 0.64, 2.01; p = 0.636) and speed/agility (OR = 1.65; 95% CI: 0.92, 2.96; p = 0.093), compared to those who did not meet all three recommendations.

Conclusion: Since meeting the three 24-h movement guidelines increased the likelihood of having higher levels in most physical fitness components, it seems necessary to promote these movement behaviors early in life, as they could serve as a gateway for improving health-related fitness in future generations.