Hisler Garrett C, Phillips Alison L, Krizan Zlatan
Department of Psychology, Iowa State University, Ames, IA, USA.
Ann Behav Med. 2017 Jun;51(3):391-401. doi: 10.1007/s12160-016-9862-0.
Diurnal preference (and chronotype more generally) has been implicated in exercise behavior, but this relation has not been examined using objective exercise measurements nor have potential psychosocial mediators been examined. Furthermore, time-of-day often moderates diurnal preference's influence on outcomes, and it is unknown whether time-of-exercise may influence the relation between chronotype and exercise frequency.
The current study examined whether individual differences in diurnal preference ("morningness-eveningness") predict unique variance in exercise frequency and if commonly studied psychosocial variables mediate this relation (i.e., behavioral intentions, internal exercise control, external exercise control, and conscientiousness). Moreover, the study sought to test whether individuals' typical time-of-exercise moderated the impact of diurnal preference on exercise frequency.
One hundred twelve healthy adults (mean age = 25.4; SD = 11.6 years) completed baseline demographics and then wore Fitbit Zips® for 4 weeks to objectively measure exercise frequency and typical time-of-exercise. At the end of the study, participants also self-reported recent exercise.
Diurnal preference predicted both self-reported exercise and Fitbit-recorded exercise frequency. When evaluating mediators, only conscientiousness emerged as a partial mediator of the relation between diurnal preference and self-reported exercise. In addition, time-of-exercise moderated diurnal preference's relation to both self-reported exercise and Fitbit-recorded exercise frequency such that diurnal preference predicted higher exercise frequency when exercise occurred at a time that was congruent with one's diurnal preference.
Based on these findings, diurnal preference is valuable, above and beyond other psychological constructs, in predicting exercise frequency and represents an important variable to incorporate into interventions seeking to increase exercise.
昼夜偏好（更广泛地说是生物钟类型）与运动行为有关，但尚未使用客观的运动测量方法来检验这种关系，也未对潜在的心理社会调节因素进行研究。此外，一天中的时间常常会调节昼夜偏好对结果的影响，而运动时间是否会影响生物钟类型与运动频率之间的关系尚不清楚。
本研究旨在检验昼夜偏好（“晨型-夜型”）的个体差异是否能预测运动频率的独特方差，以及常见的心理社会变量是否介导了这种关系（即行为意图、内部运动控制、外部运动控制和尽责性）。此外，该研究试图检验个体的典型运动时间是否会调节昼夜偏好对运动频率的影响。
112名健康成年人（平均年龄 = 25.4岁；标准差 = 11.6岁）完成了基线人口统计学调查，然后佩戴Fitbit Zips® 4周，以客观测量运动频率和典型运动时间。在研究结束时，参与者还自我报告了近期的运动情况。
昼夜偏好预测了自我报告的运动和Fitbit记录的运动频率。在评估调节因素时，只有尽责性成为昼夜偏好与自我报告运动之间关系的部分调节因素。此外，运动时间调节了昼夜偏好与自我报告运动和Fitbit记录的运动频率之间的关系，即当运动时间与个人的昼夜偏好一致时，昼夜偏好预测更高的运动频率。
基于这些发现，昼夜偏好除了其他心理结构之外，在预测运动频率方面具有重要价值，并且是纳入旨在增加运动的干预措施中的一个重要变量。
