The Key Sleep Metric That Drops for Men After 40

YOU MIGHT STRIVE to go to bed by 9 p.m., hoping to get a good night’s sleep. But if you lie awake for hours before drifting off, your sleep efficiency might be lacking, and it's probably interfering with your ability to get enough rest.

Sleep efficiency refers to the amount of time you spend actually asleep versus the time you spend in bed intending to sleep, says Zachary Strumpf, MD, pulmonary, critical care, and sleep medicine physician at University Hospitals. “It’s different than getting a better night’s sleep and reflects how effective you are at falling and staying asleep,” he says.

One of the biggest factors affecting sleep efficiency is age. Some research points to guys being hit hardest when they reach the fourth decade of life. More on that below.

How Age Impacts Sleep Efficiency

SLEEP EFFICIENCY STAYS relatively unchanged from childhood to adolescence. Then it starts to decline in adulthood, says Dr. Strumpf.

Research varies on when sleep efficiency takes a dive, but changes seem to occur in middle age (40 to 64). People’s sleep efficiency score tend to decrease from 89 to 79 percent. Sleep efficiency below 80 percent may increase a person’s mortality risk.

One study found an 18.6 percent decline in sleep efficiency between ages 40 and 100. Men specifically ages 65 to 96 were more likely to have an 80 percent or lower sleep efficiency when they were single or had a painful illness. In that study, pain, sleep medication use, and bad dreams were the main culprits for poor sleep efficiency.

Yes, sleep medication lowered people’s sleep efficiency score. Depending on the person, Dr. Strumpf says “certain medications can increase or decrease a person’s sleep efficiency or alter the proportion of time spent in REM sleep.”

How Do You Calculate Sleep Efficiency?

SLEEP EFFICIENCY IS the percentage of the time you spend asleep relative to the time you dedicate to sleep, says Nishay Chitkara, MD, director of sleep medicine at NYC Health + Hospitals/Bellevue.

Sleep efficiency scores are expressed as a percentage. To calculate it, divide the total minutes you’re asleep by the total minutes spent in bed trying to go to sleep.

Generally, a sleep efficiency of 85 to 90 percent or greater than 90 suggests that you have little trouble falling and staying asleep, he says. But if it’s lower than 80 percent, you likely have poor sleep efficiency.

If you usually go right to sleep after climbing into bed, your sleep efficiency is likely good, Dr. Strumpf says. Still, that doesn’t automatically mean you’re getting enough sleep.

“A higher sleep efficiency is not the only thing to target for restful sleep,” says Dr. Strumpf. You also need a good sleep duration, meaning getting enough total sleep, ideally at least seven hours. “Ensuring adequate sleep duration and good sleep efficiency will allow your brain to naturally cycle through all the stages of sleep you need,” he adds. These stages are controlled by the systems in the brain and usually can’t be influenced with behavioral changes.

A sleep efficiency score, whether high or low, can tell you a lot about your health. Maybe you’re knocked out when your head hits the pillow because you’ve accumulated sleep debt over the past few days. “If one is sleeping only five hours per night, the sleep efficiency may be great, but the time asleep is not sufficient,” says Dr. Chitkara. Or maybe you’re tossing and turning because your melatonin window for sleep (when your body is prepared for sleep) is off.

“A lower sleep efficiency likely needs improvement, since it could indicate that someone is not sleeping well, has poor sleep habits, or may have a medical condition that interferes with healthy sleep,” says Dr. Chitkara.

How to Improve Your Sleep Efficiency

YOU CAN GENERALLY improve your sleep efficiency by optimizing your sleep hygiene, Dr. Chitkara says. “Sleep hygiene is the set of practices that are conducive to good sleep.”

These practices include:

• Maintaining a regular sleep schedule—that is, going to bed and waking up at the same times daily
• Getting seven to nine hours of sleep a night
• Avoiding caffeine late in the day
• Going alcohol-free three to four hours before bedtime
• Avoiding TV or scrolling your phone an hour prior to sleep
• Cutting out napping
• Spending less time in bed when you’re not ready to fall asleep

Can Sleep Trackers Help?

SLEEP TRACKER APPS or other devices could help improve sleep efficiency by providing information and insights into your sleep habits, which you can use to make improvements, Dr. Chitkara says.

For instance, they can keep track of light, temperature, noise levels, and other environmental elements influencing your sleep, as well as caffeine intake and stress levels, he says. Trackers can also record health metrics, such as heart rate, movement, body temperature, and blood oxygen levels.

Fortunately, there are a number of ways to keep tabs on your sleep metrics (here are the eight best trackers for optimizing your slumber). You can also track your sleep now without wearing anything.

When to See a Doctor

ANY TIME YOU’RE having trouble falling or staying asleep, waking up several times a night, or feeling excessively sleepy throughout the day, talk to a doctor. Depending on your symptoms, they may refer you to a sleep specialist.

It’s especially important to get evaluated if these symptoms last for more than three months or if your bed partner is complaining that their own sleep is disrupted. Also get checked out if you notice any symptoms of sleep apnea, a dangerous condition where you constantly stop and start breathing when you sleep. These signs include snoring, gasping or choking during sleep, or periods of not breathing when you’re asleep.