Predicting physical activity in adolescents through enjoyment and motivation: Composite variables in mediation models

Abstract

Research indicates that adolescent physical activity (PA) engagement positively correlates with motivation and PA enjoyment. The objective was to determine if vigorous physical activity (VPA) could be predicted by PA enjoyment and motivation. Using the self- determination theory, motivation was measured for PA in the settings of leisure-time (LTPA) and physical education (PE). A cross-sectional self-report questionnaire of 715 adolescents (age 11-19) from 5 secondary schools in Switzerland was collected. The instrument included the International Physical Activity Questionnaire (IPAQ), Situational Motivation Scale (SIMS) and Physical Activity Enjoyment Scale (PACES). IPAQ scoring guidelines were implemented to compile metabolic equivalents of task (METs) for VPA. The SIMS queried motivation for PA in LTPA and PE, then aggregated scores on the relative autonomy index. A mean score was generated for PA enjoyment. Separate regression analyses were executed for LTPA and PE motivation on VPA, controlling for age, sex, and migration status. VPA was significantly predicted by motivation in both LTPA (R2=.08, β = .229, p≤ .001) and PE (R2= .04, β =.128, p≤ .001). PA enjoyment was significantly correlated (p≤ .001) with motivation for LTPA (r=.64), PE (r=.51) and VPA (r=.33). A regression analysis with PA enjoyment as additional predictor variable suggested that VPA was predicted by PA enjoyment (β= .289, p≤ .001) rather than motivation for LTPA (β=.049, p=.300). Similarly, VPA was predicted by PA enjoyment (β= .363, p≤ .001) rather than motivation for PE (β= -.058, p= .178). Higher motivation levels for LTPA and PE were related to higher adolescent VPA levels. However, the predictive power of LTPA and PE motivation disappeared when PA enjoyment was added to the models. LTPA and PE models indicated that PA enjoyment had mediation effects on the relationship between motivation and VPA.