5. Exercise and get plenty of light during the day
Supporting your circadian rhythm by avoiding artificial light at night is important, but don’t forget to enforce it during the day, too! The most important environmental factor regulating the circadian rhythm is light entering the eye, so it’s important to let your body know that it’s daytime by exposing yourself to plenty of bright light. (25) Try to spend some time outside every day, in the morning or around lunchtime if possible. Compared to outdoor light, which usually ranges from 10,000 to 30,000 lux on a clear day, ordinary indoor light is a pitiful 10 to 300 lux, not nearly bright enough to have the strong circadian-entrenching effect we want. (26)
Exercise during the day has also been shown to improve sleep quality at night. Several studies have found exercise to be effective at reducing symptoms of insomnia, and some evidence indicates that exercise may be as effective as sleeping pills.