Comparing a recommendation for self-paced versus moderate intensity physical activity for midlife adults: an RCT

目前的USDHHS指南建议成年人在宾夕法尼亚州每周至少消耗1000千卡。 可以通过每周150分钟的中等强度PA，75分钟的高强度PA， 或者是某种组合。然而，目前的估计表明，只有3.5%到43.5%的美国成年人和28%的美国成年人 超重或肥胖的成年人遵循这些建议。13-16此外，全世界的人 随着年龄的增长，组织区域变得不那么活跃。17 PA在45岁后出现更渐进的下降- 本质上，随着人们年龄的增长和体重的增加，PA的发生率会下降，而PA对健康的好处 变得更加明显。越来越多的研究19-36表明，国家指南向 强调自选强度(即，自定步调)的PA，而不是规定的中等强度PA可 更好地坚持PA计划，特别是在超重和肥胖的中年成年人中。 建议的RCT我们将进行基于现场的实验测试，假设在超重和 肥胖中年(50岁-)成年人，当PA明确时，对PA计划的坚持将会提高 建议自行调整节奏，而不是开出中等强度的处方。此方法表示一种 对于那些开始PA的新计划的人来说，心态的重要转变：即PA不需要是特定的 强度才能“算数”。如果发现自定进度的建议可以在以下几个方面更好地遵守PA 对于超重和肥胖的中年人，这可能会对PA针对这一人群的建议产生影响。 目标1：我们将进行一项随机对照试验，比较自定步速和处方中等强度PA的效果 低活动性、超重和肥胖中年(50岁-)成人PA行为的研究基于 在我们的试点中制定的程序中，所有参与者都将接受为期12个月的干预，旨在帮助他们 克服常规PA的障碍。53自变量将随机分配给自定进度或 处方中等强度的PA。主要结果将是PA的总体积(频率x持续时间x 强度)，在3、6、9和12个月时用加速度计测量。H1：建议使用自定步速PA 与基于当前公众的中等强度PA相比，将导致更多的PA(主要结果) 健康指导方针.12、54-56次级结果包括：(A)自我报告的12个月内每周PA的分钟数 计划，(B)健康变化，和(C)6个月和12个月的体重变化。 目标2：使用EMA，我们将基于我们的概念模型来检验假定的治疗效果的中介因素 (参见图1)。H2：自定节奏的PA会导致更积极的情感反应(初级中介)，因此 37次级调解人(类似于次级结果)将包括：(A) 37还将探讨PA行为的其他预测因素。

The current USDHHS guidelines recommend that adults expend at least 1000 kcal per week in PA,12 which can be obtained through 150 minutes per week of moderate intensity PA, 75 minutes of vigorous intensity PA, or some combination. However, current estimates suggest that only 3.5% to 43.5% of US adults, and 28% of overweight or obese adults adhere to these recommendations.13-16 Moreover, people across all World Health Organization regions become less active as they age.17 A more progressive decline in PA is seen after age 45- 50.15,18 In essence, PA rates tend to decrease as people age and gain weight while the health benefits of PA become more pronounced. A growing body of research19-36 suggests that a shift in national guidelines to emphasize PA of a self-selected intensity (i.e., self-paced) instead of prescribed moderate intensity PA may result in better adherence to PA programs, particularly among overweight and obese midlife adults.37,38 In the proposed RCT we will conduct a field-based experimental test of the hypothesis that, among overweight and obese midlife (ages 50-64) adults, adherence to PA programs will be improved when PA is explicitly recommended to be self-paced rather than prescribed at moderate intensity. This approach represents an important shift in mindset for those beginning a new program of PA: That is, PA need not be of a certain intensity in order to “count”. If a self-paced recommendation is found to lead to better PA adherence among overweight and obese midlife adults, this could have implications for PA recommendations for that population. Aim 1: We will conduct an RCT comparing the effects of self-paced versus prescribed moderate intensity PA on PA behavior among low-active overweight and obese midlife (ages 50-64) adults (N=240). Based on procedures developed in our pilot, all participants will receive a 12-month intervention designed to help them overcome barriers to regular PA.53 The independent variable will be random assignment to either self-paced or prescribed moderate intensity PA. The primary outcome will be total volume of PA (frequency x duration x intensity) as measured by accelerometry at months 3, 6, 9, and 12. H1: A recommendation for self-paced PA will result in more PA (primary outcome) relative to prescribing moderate intensity PA based on current public health guidelines.12,54-56 Secondary outcomes include: (a) self-reported min/week of PA over the 12-month program, (b) fitness changes, and (c) weight changes at months 6 and 12. Aim 2: Using EMA, we will examine putative mediators of treatment effects based on our conceptual model (see Figure 1). H2: Self-paced PA will lead to a more positive affective response (primary mediator) and thus greater increases in PA behavior.37 Secondary mediators (analogous to secondary outcomes) will include: (a) perceived autonomy, and (b) perceived exertion (RPE).37 Other predictors of PA behavior will also be explored.