Every year when it’s time to “fall back”, I rejoice a little. After all, it means an extra hour of sleep in the morning, and for a person who lives in a culture that secretly celebrates sleep deprivation, an extra hour of sleep is a guilty pleasure.
We all know how much sleep we need, but many of us still have trouble getting enough. Most adults need 6-8 hours of sleep each night. Those of us who don’t get enough sleep can accumulate a sleep debt.
If you have a sleep debt, you may be one of the people most affected by the time change, but not necessarily in the way that you think.
Studies show that people have disrupted sleep, decreased sleep efficiency, and less sleep overall for the first week after the time changes, both in the fall and in the spring.
The problems are thought to be related to the disruption of the sleep cycle and decreased sleep quality. The time change may cause people to take longer to fall asleep and wake up more after falling asleep. It can also cause daytime sleepiness, fatigue, and fragmented sleep, especially for those who already have a sleep debt.
The sleep disruption can last for a week or longer, leading to sleep loss as bed and awakening times adjust.
Long sleepers seem to be better able to adapt to the time change. Short sleepers, people with poor sleep quality, those who are sleep deprived, and early risers tend to be most affected and have more difficulty adjusting to the time change. Evening people will have an easier time adjusting to the fall transition and morning people will have an easier time adjusting to the spring transition.
Most of the studies have been done on the switch to Daylight Saving Time in the Spring, and have shown increased numbers of car and pedestrian traffic accidents, workplace injuries, suicides, and heart attacks, and decreased work productivity on the Monday after the switch, as well as poor performance on test scores the week after the time change.
Most of the issues are likely related to fatigue causing decreased attention and concentration. Fatigue can also worsen mood disorders. The heart attacks may be due to the lack of sleep affecting stress hormone levels. Decreased work productivity was observed as increased cyberloafing, which is non work-related internet surfing. This may be caused by reduced sleep impairing a person’s ability to self-regulate counterproductive behaviours, like procrastination. The spring time change also requires people to drive on darker roads in the morning, and the increased number of traffic accidents may be related to both fatigue and reduced visibility.
For the switch back to Standard Time in the Fall, one study showed an increase in car accidents the Sunday night, but a decrease in the number of car accidents on Monday morning. The authors were unsure why there might be an increase in car accidents on Sunday, but postulated that it may be caused by people staying up later than usual due to the time change and becoming fatigued.
Another study showed a decrease in heart attacks on the Monday morning, possibly related again to the change in stress hormone levels with an hour of extra sleep on Monday. Many people, however, are unable to take advantage of the extra hour of sleep in the morning and wake up earlier than they want to since it takes time for our body’s circadian rhythm to adjust to new sleep and wake times.
Here are some tips on how to adapt to the time change:
- Get more rest in the week leading up to and the week after the time change. Take short naps if needed, not more than 20-30 minutes.
- Catch up on your sleep debt prior to the time change. To do this, sleep in for several days in a row. Sleep until you awaken spontaneously and feel alert.
- Adjust your sleep and wake times gradually in the week before and after the time change. Parents can adjust their children’s bedtimes gradually 10-15 minutes each night.
- Circadian rhythms are affected by light. Be around natural light during the day and turn down lights in the evening. This will help your body adjust to the time change more quickly.
- No lighted screens (eg. mobile phones, tablet devices, computers) a few hours before bed. Lighted screens activate the centers in your brain that keep you awake.
- Exercise during the day.
- Sleep and wake at the same time every day.
- Avoid caffeine after early afternoon.
- Have a bedtime routine.
Also, with winter coming, here are some other things to watch out for:
- Seasonal affective disorder: moodiness or depression that is caused by the change in the season and lower light levels.
- Vitamin D levels: We don’t get enough Vitamin D in the winter in Canada from the sun, so consider taking Vitamin D3 supplements or get more in your food. Food sources of Vitamin D include milk products, fortified products, egg yolk, and oily fish.
Chronic sleep loss is associated with reduced performance, increased risk for accidents and death, and detrimental effects on psychological and physical health. Studies have shown increased numbers of car crashes and workplace accidents, as well as increased immunosuppression, heart disease, and obesity with chronic sleep deprivation. The time change is an opportunity to examine your sleep habits and schedule, to catch up on sleep debt, and to establish new habits. Select one thing that you want to change about your sleep routine, set a goal, and make a positive change in your sleep habits to improve your quality of life.
More info on how to get better sleep and sleep hygiene: http://www.anxietybc.com/sites/default/files/SleepHygiene.pdf
More info on the impact of time changes on behaviour: http://www.ncbi.nlm.nih.gov/pubmed/23477947
More information on Seasonal Affective Disorder:
More info on Vitamin D:
Dr. Yvette Lu is a Family Physician in Vancouver, BC.
website: http://yvettelu.com | twitter: @yvettelu