Amount and timing of physical activity in relation to sleep quality in the general middle-aged Dutch population: A...

To examine whether the amount and timing of moderate-to-vigorous physical activity (MVPA) was associated with sleep quality and duration in the general population.

This is a cross-sectional analysis of data of a Dutch cohort collected between 2008 and 2012. Timing of physical activity (measured using an accelerometer) was categorized as performing most MVPA in morning (06:00-12:00), afternoon (12:00-18:00), evening (18:00-00:00), or even distribution of MVPA over the day (reference). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). We estimated OR with 95 % CI of a poor score on individual PSQI components and global PSQI score using logistic regression while adjusting for relevant covariates.

We analyzed 736 participants, of whom 57 % women, aged 56 (6) years, BMI 26.1 (4.2) kg/m²). Amount of MVPA (hours/day) was associated with lower odds of fatigue-related dysfunction during daytime (OR: 0.54 0.32-0.94), but not with global PSQI score. Participants who performed most MVPA in the morning were less likely to report sleep disturbances (OR: 0.23, 95 % CI: 0.09-0.60), compared to participants with an even distribution of. Timing of MVPA was not associated with global PSQI score nor other components and CI were large.

Differences in sleep quality are unlikely to be biological mechanisms underlying the previously shown associations between timing of physical activity and metabolic health.