Based on the tenets in self-determination theory, a dual-process model of motivational processes was tested to predict accelerometer-assessed estimates of adolescents’ light physical activity (LPA), moderate to vigorous physical activity (MVPA), and sedentary time. Here, we hypothesized that (a) perceptions of psychological need support for exercise would be positively associated with LPA and MVPA and negatively associated with sedentary time via exercise-related psychological need satisfaction and autonomous exercise motivation and (b) perceptions of psychological need thwarting for exercise would be negatively associated with LPA and MVPA and positively associated with sedentary time via exercise-related psychological need frustration and controlled exercise motivation. Adolescents (N = 338; 234 female) age 11–15 years (M = 12.75, SD = .90) wore an ActiGraph accelerometer for 8 days and completed questionnaires pertaining to the self-determination-theory variables. Results showed psychological need support to indirectly and positively predict LPA and MVPA via psychological need satisfaction and autonomous exercise motivation. Although directly predictive of need frustration and indirectly predictive of controlled motivation and amotivation, the hypothesized effects from psychological need thwarting to the behavioral outcomes were nonsignificant. The current findings highlight the important role that need-supportive environments play in facilitating autonomous exercise motivation and behavior by being conducive to exercise-related psychological need satisfaction.

基于自我决定理论的原则，测试了动机过程的双过程模型，以预测加速度计评估的青少年轻度体力活动 (LPA)、中度至剧烈体力活动 (MVPA) 和久坐时间的估计值。在这里，我们假设（a）对运动的心理需求支持的看法与 LPA 和 MVPA 呈正相关，并通过与运动相关的心理需求满足和自主运动动机与久坐时间呈负相关；（b）对阻碍运动的心理需求的看法运动与 LPA 和 MVPA 呈负相关，并通过与运动相关的心理需求挫败和受控运动动机与久坐时间呈正相关。 11-15 岁青少年（ N = 338；234 名女性）（ M = 12.75， SD = .90）佩戴 ActiGraph 加速度计 8 天，并完成与自我决定理论变量相关的调查问卷。结果表明，心理需求支持可以通过心理需求满足和自主运动动机间接、积极地预测 LPA 和 MVPA。尽管直接预测需求挫败并间接预测受控动机和无动机，但心理需求挫败对行为结果的假设影响并不显着。目前的研究结果强调了需求支持环境通过有利于运动相关的心理需求满足，在促进自主运动动机和行为方面发挥的重要作用。