Effects of the FIT FIRST Teen Multisport Program on Adolescents' Physical Fitness and Well-Being: A Cluster Randomized Controlled Trial.

PURPOSE: School-based physical education (PE) can counter declines in fitness in adolescence, yet scalable, curriculum-embedded fitness programmes are scarce. We evaluated the implementation of FIT FIRST Teen (FFT), a teacher-delivered, high-intensity multisport programme across one school year.

METHODS

A cluster randomised controlled trial was conducted in 22 Danish schools (FFT, n=517; Control, n=860). Teachers in FFT were trained via a 1-day course and a manual and delivered three 40-minute lessons/week. The primary outcome was cardiorespiratory fitness, assessed via the Yo-Yo Intermittent Recovery Level 1 Children's test (YYIR1C). Secondary outcomes included handgrip strength, agility, balance, body composition, resting heart rate, and well-being. Multilevel modelling assessed the effectiveness of FFT, and exploratory latent transition analysis (LTA) was used to uncover latent fitness profiles and transitions over time in the two arms.

RESULTS

Compared with controls, adolescents allocated to FFT showed greater improvements in cardiorespiratory fitness, with a mean pre-post difference in YYIR1C distance of 106 m (p=0·009). In terms of secondary outcomes FFT showed greater gains in handgrip strength (~0.81 kg; p=0·012), and muscle mass (~0·44 kg; p<0.001). No intervention effects were observed in terms of well-being. Exploratory LTA supported a four-profile solution (high-fit, moderately-high-fit, moderately-low-fit, low-fit) and suggested that adolescents in the FFT group were more likely to remain in high-fit profile membership over time, compared to the control arm participants who tended to transition towards worse fitness profiles.

CONCLUSIONS

Compared to the control arm, a 40-wk intervention with FFT improved cardiovascular fitness, handgrip strength, and muscle mass. FFT offers an alternative to PE curricula to improve adolescents' physical fitness.