A 10-week implementation of the FIT FIRST FOR ALL school-based physical activity concept effectively improves cardiorespiratory fitness and body composition in 7–16-year-old schoolchildren

Introduction: The purpose of the present study was to investigate the impact of the FIT FIRST FOR ALL school-based physical activity program on health-related physical fitness in Faroese schoolchildren. The program aimed to add three weekly sessions of organized high-intensity physical activity to the standard weekly physical education sessions for all pupils across the entire school. Methods: A non-randomized controlled design was used to evaluate the effects of the program. Two schools participated, including one intervention school (INT; n =179) and one control school (CON; n =181), with pupils aged 7–16 years (grades 1–9). The FIT FIRST FOR ALL program consisted of three weekly 40-minute sessions of age-adjusted high-intensity physical activity over 10 weeks for the INT school, while the CON school continued their normal school program. Pre- and post-intervention assessments included cardiorespiratory fitness (Yo-Yo IR1C test), agility (Arrowhead Agility test), postural balance (Stork Stand), standing long jump performance, body composition, blood pressure, and resting heart rate. Results: A significant time × group effect (p < 0.001) was observed for cardiorespiratory fitness, which increased by 31% [23;39] in INT (p < 0.001) and remained unaltered in CON (7% [−2;16], p = 0.13). In addition, a time × group effect (p < 0.001) was observed for agility, which improved by 2.1% [1.0;3.2] in INT (p < 0.001) and regressed by 3.3% [2.3;4.4] in CON (p < 0.001). No significant between-group effects were found for standing long jump and balance. A time × group effect (p < 0.001) was observed for changes in total muscle mass, which increased by 1.4 kg [1.2;1.5] in INT (p < 0.001) and by 0.4 kg [0.3;0.6] in CON (p < 0.05). Furthermore, a time × group effect (p < 0.001) was observed for total fat percentage, which decreased by −2.3% [−2.8;−1.9] in INT (p < 0.001) and remained unchanged in CON (−0.3% [−0.7;0.1], p = 0.16). No significant time × group effects were found for blood pressure and ...