Regularly getting a good night’s sleep can have major health benefits, but the definition of “good” is more complicated than you might think, according to a scientific statement from the American Heart Association (AHA).
Traditionally, experts have talked about sleep in terms of duration. The AHA and other groups advise adults to aim for 7 to 9 hours of sleep each night—not only to avoid feeling groggy and grumpy in the morning but also to support their physical, mental, and cognitive health. Many studies have linked both short and long sleep duration to elevated blood pressure, cholesterol, and blood sugar levels; heightened risks of type 2 diabetes, heart disease, and stroke; and increased vulnerability to depression and dementia.
But it’s becoming clear that healthy sleep depends on not just quantity but quality, too, the AHA says in its recent report, published in the May issue of Circulation: Cardiovascular Quality and Outcomes. Here’s how the AHA breaks down the different “dimensions” of sleep and their relationship to your health:
Sleep continuity. This refers to your ability to stay asleep during the night. We all have to get up for a bathroom trip now and then, but if you’re regularly waking up at night, that “fragmented” sleep may have consequences—even if you’re technically getting the recommended 8-ish hours of shut-eye each night. Research suggests that sleep continuity is key to staying mentally sharp during your waking hours. And, like sleep duration, sleep continuity (or lack thereof) may affect the risk of health conditions like high blood pressure, heart disease, depression, and dementia.
Sleep timing. “Early to bed, early to rise” may, in fact, be better for your health. Studies show that people who regularly go to bed at midnight or later have increased risks of obesity, insulin resistance (a diabetes precursor), and high blood pressure. On the flip side, some research suggests that a bedtime between 10 p.m. and 11 p.m. is ideal for middle-aged and older adults. However, the evidence is not definitive: Night owls and early birds may be different in many other ways that could affect their health. More research is needed, the AHA says.
Sleep regularity. This is about having a consistent sleep routine. If your sleep patterns vary day to day, or you go to bed and rise at very different times on the weekend than on weekdays (something researchers call “social jetlag”), that may take a health toll. Studies have tied irregular sleep routines to many of the same health conditions mentioned above, including diabetes and heart disease.
Sleep satisfaction and daytime functioning. Since chronically poor sleep can make you feel lousy, it’s perhaps no surprise that people’s subjective ratings of their sleep quality and daytime functioning are also linked to various disease risks. People who feel unsatisfied with their sleep, or drowsy and low-energy during the day, tend to have higher odds of developing high blood pressure, heart disease, and other ills, versus people with more pep in their step.
There are various reasons why poor sleep might feed health problems. Our bodies use sleep as a “repair and recharge” time; the sympathetic nervous system (which governs the “fight-or-flight” response to stress) dials down, blood pressure and heart rate dip, breathing stabilizes, hormone levels change, and the brain has time to do some housecleaning. When we lack enough sleep, or uninterrupted good-quality sleep, those natural processes may be stymied.
If you think your sleep quality is less than ideal, the following tips (compiled from the AHA and Sleep Foundation) are worth a shot:
- Exercise regularly, including in the morning. Physical activity can make it easier to fall asleep at night, and morning exercise may be especially helpful: It jumpstarts your day, and if you exercise outdoors, that morning light exposure can help set your body’s internal clock that controls sleep/wake cycles.
- Limit your caffeine intake, in both amount and timing (mornings only is a good rule), and avoid alcohol and sizable meals close to bedtime.
- Take time to unwind. Give your eyes a break from electronic devices (and their stimulating blue light) for at least 30 minutes before bed. In place of screen time, set up a relaxing routine—take a warm bath or shower, listen to soft music, meditate, or read a book.
- Maintain a sleep schedule. As discussed above, consistency is key. Go to bed and get up at roughly the same time every day, including weekends. If you need a quick nap during the day, catch it no later than early afternoon and limit it to 20–30 minutes.
- Make your bedroom sleep-friendly. Set a comfortably cool temperature (around 65 degrees is a good target) and block out any light with heavy curtains or an eye mask. If neighborhood noise is an issue, consider using a fan, white noise machine, or ear plugs to drown it out.
On a final, important note, some sleep issues are beyond lifestyle fixes. Poor sleep can sometimes be related to medication side effects or to an underlying medical condition, like restless legs syndrome (RLS), obstructive sleep apnea, or benign prostatic dysplasia (BPH, which increases the urge to urinate, including at night). Talk to your doctor if you have persistent problems falling or staying asleep despite trying the tips above, or if you have additional symptoms. People with sleep apnea, for instance, may not wake up during the night but often have symptoms like chronic daytime drowsiness and loud snoring. If your bedmate is complaining about the latter, that’s a red flag.
