Effects of a goal attainment theory-based intervention on physical activity, body composition, and motivation in emerging adults with physical inactivity: A randomized controlled trial

Objectives: This study aims to assess the effectiveness of an intervention based on the goal attainment theory to levels of physical activity, body composition, and motivational variables of emerging adults with physical inactivity.

Study design: A randomized, controlled trial.

Methods: A total of 157 emerging adults with physical inactivity were randomized into the control group (n = 77) or the intervention group (n = 80). The control group received routine health education for a period of 3 months, and the intervention group used a physical activity promotion intervention model based on King's attainment theory on the basis of the control group. The primary outcome was the body composition. Secondary outcomes were examined included levels of physical activity, motivation, and self-efficacy.

Results: The results indicate that the visceral fat area was significantly lower in the intervention group (Z = -6.79, P < 0.001), along with reductions in body fat mass (Z = -2.85, P < 0.05) and body fat percentage (F = -2.78, P < 0.05). The intervention group also demonstrated higher introjected motivation (Z = 2.70, P < 0.05) and self-efficacy (Z = 4.06, P < 0.001) than the control group. Physical activity levels were significantly higher in the intervention group, with increases observed in vigorous activity (Z = 60.51, P < 0.001), moderate activity (Z = 104.90, P < 0.001), walking activity (Z = 7.37, P < 0.001), and total physical activity (Z = 91.40, P < 0.001) compared to the control group.

Conclusions: Physical activity interventions based on King's Attainment Theory can improve body composition, increase physical activity levels, improve exercise self-efficacy, and promote maintenance of healthy behaviours in emerging adults.

Trial registration: This study was registered on ClinicalTrials (NCT05697679).