Our body’s internal clock largely determines the best time to go to sleep. Gauging this clock is the tricky part. While there are some people who naturally awake in the morning ready for the day and others who take a little longer to wake up, everyone can take advantage of sleep cycles and a sleep cycle window of opportunity to achieve optimal sleep.
Before experimenting with our internal clocks and counting 90 minute sleep cycles, let’s visit circadian rhythms to inform our experimentation. The suprachiasmatic nucleus (SCN), a small region in the brain’s hypothalamus, is the control center of our internal clock, and this SCN does indeed run in 24-hour long cycles, roughly. Hormones and neural activity from the SCN regulate our sleep and wakefulness.
In addition to what’s on the inside of us, what’s on the outside plays just as big a role. Light is a strong signal to our internal clock, synchronizing our outside world with our inside world. When we’re exposed to light, our brains suppress melatonin, the sleep hormone. Here’s where there’s a hint of experimentation: there are individual differences in how soon after it grows dark that melatonin works its magic. Timing how long it takes you to feel sleepy after it’s dark will get you closer to knowing when you should go to bed.
According to sleep experts, a 10 p.m. – 6 a.m. sleep schedule is most in sync with our circadian rhythms. Between 8 p.m. and 12 a.m., there’s a window of opportunity when your brain and your body can achieve all of the non-REM and REM sleep it needs to function optimally. A good night’s sleep is comprised of five to six 90 minute sleep cycles for an average adult. During the end of a sleep cycle - a phase of light sleep - it’s easier to wake up.
Now, you can experiment with your circadian rhythms and 90 minute sleep cycles. If it takes you 15 minutes to fall asleep, then go to bed at 9:45 p.m. or 11:15 p.m. to wake up feeling refreshed at 7 a.m. (we’re counting 90 minute cycles here).
Or if you count backward from the time you want to wake up, the time you should go to bed depends on your age: adults aged 18 to 60 years old should average between seven and nine hours of sleep. Elderly adults (older than 60) may average seven to eight hours of sleep. If you’re 50 years old, and you want to wake up at 7, go to bed at 11 p.m.
If you need the objective data of technology to assist in your quest to find the perfect bedtime, there are a number of sleep monitors in all shapes and sizes. Some are more complicated than others. You can find more about health related gadgets on various sites online like SmartifyLife where you can check out how sleep gadgets work and review of popular tools.
Once you find your optimal bedtime, stay consistent. Your body’s internal clock will stay on schedule. Also, develop a nighttime routine. Be sure to sleep in a cool, dark room with comfortable bedding. Good night!