Get Into the (Circadian) Rhythm: Understanding your biological clock

If you’ve ever suffered from jet lag, you know how out-of-sorts you feel when you’re out of tune with the solar day. Humans have an innate circadian rhythm that’s set to a 24-hour clock. This rhythm not only controls wakefulness, but also affects body temperature, metabolism, and the release of hormones. That explains why you experience jet lag: when you fly to a different time zone, your body is synced with your starting time zone, and it takes a few days for your biological clock to re-adjust. Since the main influence on our circadian rhythms is light, it’s all too easy to upset the natural cycle. Everyday disruptions might include being awakened by an alarm for school, sleeping late on weekends, nights spent in front of glowing screens, and underexposure to daytime sunlight. Not only do sleep and alertness suffer; in the long run, out-of-tune circadian rhythms have been linked to adverse outcomes such as obesity, diabetes, depression and metabolic disorders. To help regulate your sleep-wake cycle, try these tips:

  • Use the right type of light: Keep bright light out of bedrooms and bathrooms at night, especially blue light, since it can delay the release of sleep-inducing melatonin and increase alertness. Use dim red light instead. One option is to try a programmable smart light system that allows you to adjust lighting color and intensity.

  • Control electronics: Turn off the TV and put your electronic devices away 1-2 hours before bedtime to avoid blue light. If you must look at a screen before bed, use features that reduce blue light at nighttime, such as iPhone’s Night Shift or Android’s Twilight.

  • Get outside: When you spend time exposed to natural light, your internal circadian clock better syncs with the solar day.

  • Take gradual steps: Adjust your schedule by 15 minutes each day, earlier or later, until you find your sweet spot. Then stick to a consistent sleep schedule (even on the weekends!).