Effects of a gamified mobile health intervention on physical activity, cognitive function, and mental Health: a randomized controlled trial (Preprint)

BACKGROUND College students commonly experience suboptimal health conditions, including insufficient physical activity, excessive body weight, and declining physical fitness. Traditional interventions face low adherence, while gamified mobile health (mHealth) programs may improve engagement and outcomes. OBJECTIVE This study aims to evaluate the feasibility and effectiveness of a gamified, incentive-based mHealth intervention on physical activity, physical fitness, body composition, cognitive function, and mental health. METHODS A parallel-group randomized controlled trial was conducted with 160 college students (18–25 years, BMI 18.5–30.0) from Yantai University, equally distributed by gender. Participants were randomly assigned to an intervention group (IG, n=80) or control group (CG, n=80). All wore a fitness watch and used the “Shouti Fitness” app with a standardized weekly activity target (≥150 min of moderate-to-vigorous physical activity [MVPA] or ≥900 MET-minutes). CG participants only met these basic goals, while IG engaged in an additional gamified program featuring team-based competition, points, rankings, and rewards. The intervention lasted 8 weeks. Assessments were performed at baseline (T0) and post-intervention (T1). Outcomes included: (1) physical activity (steps, MVPA, METs); (2) adherence (goal completion, data synchronization); (3) physical fitness (aerobic endurance, vital capacity, flexibility, muscular endurance); (4) body composition (body fat, skeletal muscle, BMI, basal metabolic rate); (5) cognitive function (inhibitory control, working memory, flexibility); and (6) mental health, using the Self-Rating Depression Scale (SDS) and Self-Rating Anxiety Scale (SAS). RESULTS After the 8-week intervention period, the IG demonstrated: The intervention group (IG) had a lower attrition rate (2.5% vs. 5%) and significantly higher physical activity than controls (steps +2,514; MVPA +28 min; METs +310, all P<0.01). Adherence was better in IG, with higher goal completion (+11.4%) and synchronization rates (+13.6%, P<0.05). IG showed greater body composition improvements (↑muscle +0.54 kg, ↓fat –0.46%, ↑BMR +7.8 kcal/day, P<0.05), though weight and BMI were unchanged. Fitness gains included endurance (–6.5 s run), vital capacity (+190 mL), flexibility (+1.8 cm), and female sit-ups (+4.5 reps, all P<0.05). No differences were found in strength or explosive power. Cognitive benefits were limited to flexibility (–29 ms, P<0.05). IG also showed a larger reduction in depression scores (–2.0, P<0.01), while anxiety remained unchanged overall, with increases in some high-baseline cases. CONCLUSIONS Gamified mHealth interventions significantly improve physical activity, adherence, fitness, and body composition in students, but effects on strength, higher cognition, and anxiety remain limited. Integrating resistance training, CBT, and dietary strategies may yield broader benefits.