Objective: Based on the self-determination theory, to explore the relationship between motivation quality and college students' physical fitness and the mediating role of physical activities from the perspective of the coexistence of autonomous motivation(AM) and controlled motivation(CM).
Methods: From October to November 2019, a total of 682 freshmen and sophomores(252 males and 430 females) were recruited with cluster-sampling method from 4 colleges and universities in Wuhu City, filled with questionnaires of Perceived Locus of Causality scale and Godin's leisure-time physical activity questionnaire, and tested physical fitness according to China National Fitness Test Program after 6 weeks. The data were analyzed by polynomial regression combined with response surface analysis and mediation effect test.
Results: Physical fitness presented a "convex" curve increase with the consistency of AM and CM(a1=1.547, a2=1.254, P<0.01). The physical fitness of high AM-high CM combination was higher than that of low AM-low CM combination(Z_(hat)=3.111, 95% CI 0.446-5.896). Under the condition of AM and CM differentiation, physical fitness was higher when the discrepancy was such that AM was higher than CM(a3=5.280, P<0.01; a4=0.232, P>0.05). AM positively predicted physical activity in a nonlinear form(β_( AM)=1.605, β_(AM)~2=1.602, P<0.01). Physical activity showed a "convex" change with the consistency of AM-CM(a1=0.811, P > 0.05; a2=1.618, P <0.01), but there was no significant difference in the level of physical activity between high and low AM-CM combination(Z_(hat)=1.407, 95% CI-0.084-3.391). Physical activity was higher in high AM-low CM combination than that in high CM-low AM combination(Z_(hat)=5.008, 95% CI 2.348-7.113). Matching of AM and CM influenced college students' physical fitness directly(β=0.453, P<0.01) and indirectly through physical activity(β=0.184, 95% CI 0.145-0.240).
Conclusion: The coexistence of AM and CM effects physical fitness through their consistency and inconsistency matching.
Keywords: autonomous motivation; controlled motivation; physical activity; physical fitness; polynomial regression; response surface analysis.