Faculty of Human Kinetics, Technical University of Lisbon, Lisbon, Portugal.
Med Sci Sports Exerc. 2011 Apr;43(4):728-37. doi: 10.1249/MSS.0b013e3181f3818f.
This study evaluated exercise-related predictors of successful long-term weight control in women by analyzing the extent to which sustained exercise participation and self-determination theory (SDT)-based exercise motivation variables mediated the impact of a behavioral weight control intervention on 3-yr weight change.
Longitudinal randomized controlled trial consisting of a 1-yr SDT-based intervention and a 2-yr follow-up with 221 female participants (means ± SD: age = 37.6 ± 7 yr, body mass index = 31.6 ± 4.1 kg·m(-2)). The tested model incorporated experimentally manipulated perceived need support, motivational regulations, and 2-yr exercise adherence as mediators of the intervention's impact on 3-yr weight change. Paths were tested using partial least squares analysis. Where there were significant intervening paths, tests of mediation were conducted.
Treatment had significant effects on 1- and 2-yr autonomous regulations, 2-yr physical activity, and 3-yr weight change, fully mediated by the tested paths (effect ratio = 0.10-0.61). Moderate and vigorous exercise at 2 yr had a significant effect (P < 0.001) on weight loss success at 3 yr and partially mediated the effect of treatment on weight change. The 2-yr autonomous regulation effects on follow-up weight change were only partially mediated by physical activity (effect ratio = 0.42).
This application of SDT to physical activity and weight management showed that not all types of motivation predict long-term behavioral outcomes and that sustained moderate and vigorous exercise mediated long-term weight change. It provides strong evidence for a link between experimentally increased autonomous motivation and exercise and long-term weight loss maintenance. Results highlight the importance of interventions targeting the internalization of exercise behavioral regulation and making exercise and physical activity positive and meaningful experiences rather than simply focusing on immediate behavior change in overweight/obese women.
本研究通过分析持续参与运动和基于自我决定理论（SDT）的运动动机变量在多大程度上对行为体重控制干预对 3 年体重变化的影响进行中介，评估与成功长期体重控制相关的运动预测因素。
这是一项纵向随机对照试验，包括为期 1 年的 SDT 干预和为期 2 年的随访，共有 221 名女性参与者（平均值 ± 标准差：年龄=37.6±7 岁，体重指数=31.6±4.1kg·m(-2)）。所测试的模型纳入了实验性操纵的感知需求支持、动机规则以及 2 年的运动依从性作为干预对 3 年体重变化影响的中介。使用偏最小二乘法分析检验路径。对于存在显著干预路径的情况，进行了中介测试。
治疗对 1 年和 2 年的自主规则、2 年的身体活动和 3 年的体重变化有显著影响，这些影响完全由所测试的路径介导（效应比=0.10-0.61）。2 年时的中度和剧烈运动对 3 年时的减肥成功有显著影响（P<0.001），并部分介导了治疗对体重变化的影响。2 年时的自主调节对随访体重变化的影响仅部分由身体活动介导（效应比=0.42）。
SDT 在身体活动和体重管理中的应用表明，并非所有类型的动机都能预测长期行为结果，并且持续的中度和剧烈运动介导了长期体重变化。这为实验性增加自主动机与运动以及长期减肥维持之间的联系提供了有力证据。结果强调了针对运动行为调节内化的干预以及使运动和身体活动变得积极和有意义的重要性，而不仅仅是关注超重/肥胖女性的即时行为改变。
