THE IMPACT OF HOLIDAYS AND SEASONAL CHANGES ON SLEEP AND ACTIVITY LEVELS

Our sleep and movement patterns vary significantly by day-of-the-week and season, as well as during annual events like the Christmas to New Year holiday/vacation period, and daylight-saving time changes according to a recent Australian study.

Researchers from the University of South Australia and the University of Queensland conducted a cohort study including 368 adults who wore activity trackers 24 hours/day for 12 months to collect data on sleep, sedentary behaviour and physical activity levels. They found differences in sleep and activity levels between days of the week, seasons and annual events:

• sleep was longer on weekends compared to weekdays, gradually decreasing from Monday to Friday followed by a significant increase on weekends.
• sleep was slightly longer during autumn and winter relative to summer.
• sedentary behaviour was longer during winter compared to summer, and during weekdays compared to weekends, varying by approximately 60 minutes/day across the week.
• levels of light physical activity were shorter in autumn and winter than in summer.
• levels of moderate-to-vigorous physical activity were lower during winter and higher in spring compared to summer and lower during weekdays compared to weekends.
• after the Christmas to New Year period, sleep and sedentary behaviours were both longer and levels of light physical activity were lower.
• sedentary behaviour was longer after the end of daylight savings time.

In a second study published in 2024, the same researchers looked at the impact of vacations on daily movement patterns. They studied 308 adults who wore fitness trackers 24 hrs/day for 13 months. During this time, the participants took an average of 2.6 vacations of 12 days duration on each occasion.
The researchers found that daily sleep increased by approximately 20 minutes, light physical activity by 3 minutes and moderate-to-vigorous physical activity by 5 minutes while sedentary behaviour decreased by almost 30 minutes while participants were on vacation. Perhaps not surprisingly, the most favourable changes in activity levels were seen for outdoor recreation vacations. After returning from holidays, participants continued to sleep longer for another 2 weeks, while moderate-to-vigorous physical activity levels returned to pre-vacation levels, and levels of light physical activity and sedentary behavior were significantly lower for 1-4 weeks.

The findings of these two studies are consistent with a 2021 systematic review and meta-analysis looking at annual, seasonal, cultural and vacation patterns in sleep, sedentary behaviour and physical activity. The review of 17 studies from 14 countries found evidence for seasonal variation in activity patterns, with sleep highest in autumn, sedentary behaviour highest in winter, and both light physical activity and moderate-to-vigorous physical activity highest in summer when compared to the yearly average. Light physical activity was higher during vacations, and sleep increased after the spring daylight savings transition and decreased after the autumn transition.

So, how can you use these findings to optimise your own sleep and physical activity levels throughout the year?

1. Move activity indoors for winter. Schedule indoor or home-based exercise routines during autumn and winter to help counteract the drop in physical activity and rise in sedentary behaviour typically seen in colder months.
2. Plan post-holiday movement. Be proactive about ways to stay physically active after returning from holidays or major festive periods when research shows that sedentary behaviour tends to increase and light activity decreases.
3. Prioritise weekday sleep and activity. Take advantage of the extra time for sleep and movement on the weekends, but also try to maintain a consistent sleep schedule throughout the week and look for ways to incorporate more activity into your weekdays.
4. Plan outdoor recreation holidays. This type of vacation results in the most favourable overall changes, including increased sleep, increased light and moderate-intensity physical activity and decreased sedentary behaviour.