Individual Differences in Diurnal Preference and Time-of-Exercise Interact to Predict Exercise Frequency

Area of Science:

• Chronobiology
• Exercise Science
• Behavioral Psychology

Background:

• Diurnal preference (chronotype) is linked to exercise behavior, but objective measures and psychosocial mediators are understudied.
• The moderating role of exercise timing on chronotype-exercise frequency relationship is unknown.

Purpose of the Study:

• Examine if diurnal preference predicts exercise frequency using objective and self-reported measures.
• Investigate psychosocial mediators (intentions, control, conscientiousness) of this relationship.
• Test if typical exercise timing moderates the chronotype-exercise frequency link.

Main Methods:

• 112 healthy adults wore Fitbits for 4 weeks to objectively measure exercise frequency and timing.
• Baseline demographics and self-reported exercise data were collected.
• Psychosocial variables were assessed at study conclusion.

Main Results:

• Diurnal preference predicted both objective and self-reported exercise frequency.
• Conscientiousness partially mediated the link between diurnal preference and self-reported exercise.
• Exercise timing moderated the relationship: congruent timing enhanced the positive effect of diurnal preference on exercise frequency.

Conclusions:

• Diurnal preference is a significant predictor of exercise frequency, independent of other psychological factors.
• Incorporating chronotype into exercise interventions may improve efficacy.
• Exercise timing congruent with diurnal preference is associated with higher exercise frequency.