Tuning into circadian rhythms for better sleep
Circadian rhythms are daily cycles that run in our bodies to control essential processes and functions.
One of the most well-known is our daily cycle of sleeping and being awake. It aligns with a master clock in our brain, which is influenced by environmental things like temperature and sunlight.
When our sleep-wake circadian rhythms lose some connection to our master clock, or they get out of sync, we can struggle to sleep well, even though we’re feeling tired. We can also feel a little nauseous, because our digestive systems are out of sync and underperforming.
Long-distance travel and shift work often disrupt natural rhythms
Common causes of disrupted circadian rhythms include jet lag and shift work. You may have experienced either of these in the past. Flying part way around the world moves you to a different time zone, so your body clock is no longer in sync with the new light and dark cycle. People who work nights and sleep during the day often struggle to get their body functions to change their natural timing. This is particularly difficult when someone is regularly rotating between day and night shifts.
People who fly a lot, perhaps for work, have found that immediately aligning their activities to the destination time zone helps to speed up the necessary adjustment. So, if they board a plane at night, but it’s early morning where they headed, they’ll have a light breakfast-style meal after take-off and try to stay awake with their cabin light on and watching a well-lit screen. As soon as they arrive, they expose themselves to light and darkness according to what’s happening outside. A walk in the sun on the first day there, no matter how drowsy they feel, helps their body clock to more quickly reset more quickly.
Our circadian rhythms and sleep quality change with age
As you get older, your body clock very gradually shifts to an earlier schedule. You might start waking earlier and feeling drowsy in the evening or late afternoon. You may also be spending more time indoors, sometimes in dimly lit rooms, and not exercising as much as you used to. If so, you may not be giving your body clock the clear daylight and energy-use signals it needs to stay on track.
The body clock in most older adults has a natural bedtime of around 8pm and a wakeup time about eight hours later - at 4am. Although you may stay up later, your body clock will still want to wake you up about 4am. This results in loss of sleep.
Older people also spend less time in deep sleep and rapid eye movement (REM) sleep, which are the most restful types. With more time in light sleep, you might wake and fall back asleep several times a night, sometimes getting the impression you didn’t sleep well at all.
It’s also harder for older people to adapt to changes in their bedtime and their body clocks don’t respond as well to environmental signals, like daylight and dark. That means you may require regular reminders to stay on track.
When you don’t get a good eight-hour sleep, you can feel tired, a bit dopey and confused, or even depressed. If you’re struggling to sleep well, it’s a good idea to raise it with your doctor or caregiver. In the meantime, here are some tips that may help.
How to keep your circadian rhythms in good shape
If you’re having trouble sleeping, your circadian rhythms could need a tune up. There’s no way to control them directly, but here are some tips for getting back on track:
- Get out in the sun: Daily exposure to lots of natural light, especially in the mornings, gives your body clock one of the strongest signals of where you are in the day/night cycle. You could even take your sunglasses off for a while.
- Exercise every day: Undertaking some sort of activity every day also reminds your body that this is the regular active time, not the sleeping time. It doesn’t have to be strenuous activity, just whatever is safe and healthy for you.
- Stick to the same bedtime: Keeping your bedtime and wake-up time consistent will give your body clock a clear signal of when to help you sleep and when to keep you alert.
- Avoid bright light before bed: Try turning off the TV, ignoring your mobile phone and dimming the house lights for up to an hour before bed time. This lets your body clock know it’s time to start adjusting your systems for sleep.
- Keep afternoon naps short: We all run lower on energy towards the end of the day and sometimes a quick nap is just the lift we need. By keeping it to less than 30 minutes, you’ll avoid deep sleep and wake feeling more refreshed. You also won’t confuse your body clock by imitating bedtime.
- Avoid stimulants like caffeine: Everyone’s caffeine tolerance is different, but if you’re having trouble getting to sleep you could try not having any caffeine after midday. Caffeine-free tea lets your still enjoy a nice warm drink without over-riding your natural sleepiness cycle.
Photo by Clément Falize on Unsplash