The Roles of Grit and Motivation in Predicting Children's Leisure-Time Physical Activity: One-Year Effects.

In this study, we tested two alternative models for investigating the ability of dimensions of personal grit (consistency of interest and perseverance of effort) and autonomous motivation to predict the leisure-time physical activity (LTPA) over a one-year period of 256 youth (aged 11-15 years at the beginning of the study). Specifically, we compared a model in which dimensions of grit were assumed to predict LTPA through autonomous motivation with a model in which autonomous motivation was assumed to predict LTPA through dimensions of grit. We tested the two models using variance-based structural equation modelling with Warp PLS v7.0 software. Both models showed a good fit with the data and equally explained 41% of the variance in LTPA over this one-year time period. However, the model based on the total effect of autonomous motivation (β = 0.448,  < 0.001, ES = 0.229) on LTPA through the dimensions of grit was stronger than the model based on the total effect of perseverance of effort (β = 0.356,  < 0.001, ES = 0.126) on LTPA through autonomous motivation, and the total effect of consistency of interest was not significant (β = -0.029,  > 0.05, ES = 0.003). Our findings underscore the relatively greater importance of the interplay between autonomous motivation and perseverance of effort, versus consistency of interest, in predicting LTPA among youth over a one-year period.