Sleep is vital to good health and well-being. As you sleep, your body works to support healthy brain function and maintain physical health. A lack of sleep can be harmful over time. The National Heart, Lung, and Blood Institute reports that about 50 to 70 million Americans have sleep disorders, and 1 in 3 adults are not getting the recommended amount of uninterrupted sleep they need to protect their health. Not only does sleep deficiency raise the risk for some chronic health problems, it also affects how well you think, react, work, learn, and get along with others. Ongoing sleep deficiency is linked to increased risk of heart disease (i.e., high blood pressure and stroke) diabetes, kidney disease, and obesity. Recent studies have shed more light to the importance of undisrupted sleep.

How Exercise Impacts Sleep Quality

Exercise is an important part of a healthy lifestyle. Working out regularly helps control your weight, fight heart disease, and even boost your mood. Also, exercise has been linked to improving your sleep quality at night and promoting greater alertness during the day. To maximize your sleep results, it is important to understand the exercise sleep connection, including how much to exercise and when to exercise.

Exercising in the morning or afternoon raises your body temperature a few degrees. When your body temperature drops back to its normal range in the evening, this can trigger feelings of drowsiness and helps you drop off to sleep. Moreover, exercising outdoors exposes you to natural light, which is an important element that helps the body establish a good sleep-wake cycle.

Surprisingly, you do not need to spend half the day in the gym to see an impact on your sleep. Completing about 30 minutes of moderate to vigorous exercise five times a week will not only help improve your sleep quality, but also allows you to meet the national guidelines for physical activity. Even if you cannot fit in 30 minutes of activity, walking, swimming, or biking for just 10 minutes can improve your sleep. Take a brisk walk around the neighborhood or a quick bike ride with the children and reward yourself with a good solid night’s sleep.

Impact of Light on Sleeping Patterns and Health

Scientists at NIEHS have found an association between any exposure to artificial light at night while sleeping and weight gain in women. The Sister Study, a cohort study examining risk factors for breast cancer and other diseases in women, used questionnaire data from 43,722 participants aged 35-74 years old.

The women had no history of cancer or cardiovascular disease, did not work shift-work, were not daytime sleepers, and were not pregnant when the study began. Women were asked if they slept with no light, a small nightlight, light outside of the room, or a light or television on in the room. Results indicated that women who slept with a light or television on were 17% more likely to have gained five kilograms (approximately 11 pounds), or more over follow-up five years later. Weight gain was not associated with using a small nightlight. Light coming from outside the room showed a more modest association. The research results suggest women can reduce chances of becoming obese. So, turn off the lights and your television at bedtime to reduce your chances of obesity.

Lack of Sleep May Increase Your Risk for Diabetes and Heart Disease

A recent study found higher blood sugar (or blood glucose) levels in African Americans with disrupted sleep. About 800 African American men and women who had home sleep apnea testing participated in the study. Study participants wore a device that measured their sleep for a week and they kept a sleep diary. How long people slept, how often they woke up during the night, and changes in sleep patterns were examined. These findings were compared with blood glucose levels taken in a clinic. Higher glucose levels were found in those with either sleep apnea or disrupted sleep patterns. Levels were 14% higher in people with the most severe sleep apnea.

A five-year heart study found that older adults with irregular sleep patterns are nearly twice as likely to develop cardiovascular disease (CVD) as those with more regular sleep patterns. The study involved 1,992 men and women who were part of the National Heart, Lung, and Blood Institute-funded Multi-Ethnic Study of Atherosclerosis. The participants were between the ages of 45-84, lived in communities across the United States, and did not have CVD at the start of the study. CVD events, including heart attack and stroke, or death from CVD-related causes, were observed in 111 participants. The study suggested that an irregular sleep pattern may be a risk factor for CVD, and that maintaining regular sleep patterns could help prevent heart disease just as physical activity, a healthy diet, and other lifestyle measures6. Consistent with previous studies, this study found that racial/ethnic minority populations, particularly African Americans, displayed a stronger association between irregular sleep and CVD than did whites. While researchers are still unclear as to the exact biological mechanisms behind the sleep irregularity and CVD link, they speculate that multiple factors, including harmful disturbances in the body’s circadian rhythm, may play an important part.

Eight Tips for Ensuring Good, Quality Uninterrupted Sleep

1. Go to bed and wake up at the same time every day. For children, have a set bedtime and a bedtime routine. Don’t use the child’s bedroom for timeouts or punishment.
2. Try to keep the same sleep schedule on weeknights and weekends. Limit the difference to no more than about an hour. Staying up late and sleeping in late on weekends can disrupt your body clock’s sleep-wake rhythm.
3. Use the hour before bed for quiet time. Avoid strenuous exercise and bright artificial light, such as from a TV or computer screen. The light may signal the brain that it’s time to be awake.
4. Avoid heavy and/or large meals within a couple hours of bedtime. (Having a light snack is okay.) Also, avoid alcoholic drinks before bed.
5. Avoid nicotine (for example, cigarettes) and caffeine (including caffeinated soda, coffee, tea, and chocolate). Nicotine and caffeine are stimulants, and both substances can interfere with sleep. The effects of caffeine can last as long as eight hours. So, a cup of coffee in the late afternoon can make it hard for you to fall asleep at night.
6. Spend time outside every day (when possible) and be physically active.
7. Keep your bedroom quiet, cool, and dark (a dim night light is fine, if needed).
8. Take a hot bath or use relaxation techniques before bed.

Do You Think You Have a Sleep Problem?

If so, talk to your doctor. Be prepared to answer questions about work and exercise routines, and caffeine, tobacco, alcohol, or any medicine use. Also consider keeping a sleep diary for a couple of weeks. The diary should indicate when you prepare for sleep, wake up, and take naps, and how alert or rested you feel throughout the day. Share the information from your sleep diary with your doctor.