The surprising heart risks of too much sleep and exercise

You’ve probably heard a lot about how getting exercise and sleep can help you avoid heart troubles in the future. But getting too much of either can actually increase your risk of heart disease.

It seems counterintuitive. After all, we’re constantly told that exercising regularly and getting enough sleep are vital to staving off obesity, high blood pressure, stroke and, of course, heart disease. And it’s true. Exercise and sleep are important components of a healthy lifestyle. So, wouldn’t exercising even more and getting lots of sleep make us healthier and less prone to heart disease?

Surprisingly, the answer is no. Excessive sleep and over-exercising can increase your risk for heart disease, just like not getting enough sleep or exercise can. In many disciplines, from economics to communication, this phenomenon is known as the “Goldilocks effect,” referring to the children’s story of “Goldilocks and the Three Bears.”

Here’s how can you balance your sleep and exercise to find the amount that isn’t too much or too little, but instead “just right” for your heart health.     

How sleep affects the heart

There is still some debate about the exact amount of sleep that’s ideal for adults. However, researchers have reached a consensus on the optimum range. Almost everyone needs between seven and nine hours of sleep every day. And no, you can’t “catch up” on the weekends. It’s much better for your body’s circadian rhythm–the natural sleeping and waking cycle–to go to bed and wake up at a relatively consistent time each day.

Some people are naturally long sleepers, about two percent of the population. These people need 10 to 12 hours of sleep, or they feel tired and groggy throughout the day. However, most people should not be sleeping more than nine hours per day.  

Oversleeping has been linked to increased inflammation–in which the body’s immune system attacks healthy tissue. Chronic inflammation, or inflammation that occurs over months or even years, can put you at greater risk for cancer, diabetes, heart disease and many other health problems.

Getting too little sleep or too much sleep can increase inflammation levels. But considering that fewer people are aware of the dangers of oversleeping compared to undersleeping, it’s important to emphasize that both can lead to heart problems in the future. A study of the National Health and Nutrition Examination Survey found that, compared to people who get six to eight hours of sleep, those who slept:

  • Less than six hours: Had a doubled risk of stroke or heart attack
  • More than eight hours: Had a doubled risk of angina – chest pain due to reduced blood flow – and 10 percent higher risk of coronary artery disease

If you’re having trouble getting between seven and nine hours of sleep each night, bring it up to your doctor at your next physical. While short-term sleep problems aren’t likely to cause lasting damage, developing poor sleep habits can put you at higher risk for heart trouble as well as other problems later in life.

How exercise affects the heart

On the whole, Americans don’t exercise nearly enough. About half of U.S. adults don’t get enough aerobic physical activity – the heart-strengthening exercises known as “cardio.” Aerobic exercise is one of the best ways to safeguard against future heart disease and improve your overall health. However, too much vigorous aerobic exercise can also be detrimental to your heart health.

Like a few days of getting too little sleep, brief bouts of high-intensity cardio followed by periods of rest won’t do lasting damage. In fact, it can make your heart stronger. Problems arise when extreme athletes – such as long-distance runners, rowers, swimmers and cyclists – perform vigorous exercise regularly.

Intense aerobic physical activity puts a strain on your heart. Over time, repeated strain changes the very structure of the heart, enlarging the arteries and right ventricle and causing thick scar tissue to form in the heart’s two atria. These adaptations have been linked to heart problems in some people, though more research is needed for us to draw definitive conclusions.

There are many misconceptions about how intense exercise needs to be to achieve the best results. I find that many people believe they have to be totally out of breath and drenched in sweat to get a “good workout,” but the reality is that, as far as your heart is concerned, you’ll maximize your exercise benefits with regular moderate exercise, like a brisk walk. What defines “moderate” exercise? You should sweat a little and be able to carry on a conversation with someone without too much difficulty.

The American Heart Association recommends 150 minutes of moderate physical activity per week, or 75 minutes of vigorous exercise, or some combination of both. I suggest doing 30 to 60 minutes of moderate exercise on most days of the week. That’s a healthy habit that you can continue through your whole life. 

This doesn’t mean you shouldn’t give that marathon or triathlon you’ve always wanted to do a try. I’ve finished 11 marathons and a 50-mile race, so I know the allure of such events. The positives of endurance training are many: fitness, strength, even psychological. But we need to remember that more isn’t always better. Talk to your doctor before beginning to train for such endurance events. As for me, I still enjoy running and believe strongly in the benefits of exercise, although I’ve moderated my distance over the years, opting for a morning jog on the C&O canal as my favorite run!

Most people don’t have to worry about exercising too much or oversleeping. In fact, they should be concerned about too little exercise and sleep! But for extreme athletes and chronic sleepers, these issues can lead to heart problems in the future. The trick to the Goldilocks effect of sleep and exercise is finding a balance that makes you feel “just right.”

 

Request an appointment online or call 844-333-DOCS to talk to a doctor about how your sleep and exercise routine affects your heart.

 

Chief of Cardiology, MedStar Heart & Vascular Institute at MedStar Washington Hospital Center
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