Chronotypes and objectively measured physical activity and sedentary time at midlife

Area of Science:

• Chronobiology
• Public Health
• Exercise Science

Background:

• Chronotypes, reflecting circadian timing of alertness and sleep, are categorized as morning, day, or evening.
• Previous research suggests a link between evening chronotype and reduced physical activity (PA) and increased sedentary time (SED).

Purpose of the Study:

• To objectively investigate the association between chronotype and measured physical activity (PA) and sedentary time (SED).

Main Methods:

• Utilized data from the Northern Finland Birth Cohort 1966 study, including 5156 participants.
• Objectively measured total PA and SED using wrist-worn accelerometers over 14 days.
• Defined chronotypes using the Morningness-Eveningness Questionnaire and analyzed associations using adjusted general linear models.

Main Results:

• Evening chronotype was associated with lower objectively measured PA in both men and women.
• Men with day and morning chronotypes exhibited higher PA and lower SED compared to evening chronotypes.
• Women with morning chronotype showed higher PA, but no significant association with SED was found.

Conclusions:

• Evening chronotype is consistently linked to reduced objectively measured physical activity and increased sedentary time, particularly in men.
• Chronotype should be considered as a factor in designing effective physical activity promotion interventions.