Our body clocks (circadian rhythm) keeps us running smoothly and on time. Our 24-hour cycle controls body temperature, hunger, and sleep. And that clock is wired directly to our eyes, so light has a big effect on it. Upon awaking in the morning, light floods our brain. It turns certain genes on and off to get us revved up for the day. It also tells our brain to stop making melatonin, a hormone that makes us sleepy. Later, as the day fades, darkness flips the melatonin switch back so that we can get to sleep.
Body Clocks: Shifts With Age
As you get older, your body clock goes through a few changes. Newborns sleep up to 17 hours a day, while teens need more like 10. Teens also tend to stay up later and sleep in longer. As you move into adulthood, you typically settle in to 7 to 9 hours of sleep a night. And after age 65, you might see other shifts, like waking up earlier, and having less REM sleep. REM sleep is important for memory processing and a host of mental tasks.
Body Clocks: Your Daily Schedule
You might think you can pull a string of late nights and make up the lost sleep on the weekend. But that’s like being on a leaky boat and thinking, “I’ll bail it out on Saturday.” Your body craves routine, and late nights and sleeping in can keep you out of sync. If you do grab some extra shuteye, limit it to an hour, two at the most.
Body Clocks: Jet Lag
Going from L.A. to New York may not seem like a big deal. But the next morning, when your alarm clocks says 7 a.m., your body clock’s groaning that it’s only on 4 a.m. You’ll adjust, but it might take a few days. The more time zones you cross, the worse it is, especially if you fly east. And changing our clocks twice a year for daylight saving time is like jet lag without leaving the ground.
Body Clocks: Consistency Is Important
When your clock’s off, it doesn’t just mess up your sleep. Your hormones, digestion, and even your immune system can take a hit, too. Scientists believe fighting against your clock can make you sick. Some studies show connections between circadian rhythms that are out of whack and conditions like cancer, diabetes, bipolar disorder, and obesity.
Body Clocks: Resetting The Timer
When you need to get yourself back on track, nothing beats boring. A regular schedule, day in and day out, is one of the best things you can do. Go to bed at the same time each night, then wake up at the same time each morning. Rinse and repeat. Aim to keep the time the same within half an hour on both ends, and you’ll be off to a strong start.
Body Clocks: Yes To Exercise
Yes. People who hit the gym in the early morning tend to get better sleep all around. An afternoon workout can be a good idea, too. Your body temp is higher then, which is good for your muscles. But don’t exercise within 2 hours of your bedtime, because it may rev you up and make you more alert.
Body Clocks: No Late Snacking
It’s not a good idea to eat right before bed. The best bet is to fill up at dinner at the same time each night, a few hours before bed. And stay away from heavy meals, spicy foods, and caffeine in the later hours.
Body Clocks: Protocol For Shift Workers
If you wake up at night to go to work, flip on the bright lights as soon as you get up. Quick exercises like jumping jacks or a short walk can help, too. At work, keep it as bright as you can. If you head home when it’s light out, wear sunglasses, and once you’re back at your place, use blackout curtains in your bedroom to block out as much light as possible.