Resting Heart Rate, Exercise, and Risk of Dying

June 19, 2016

by Cathe Friedrich

The “normal” resting heart rate is between 60 and 100 beats per minute. Despite what the medical books tell you, many doctors and health care professionals believe it should be lower. That’s partly because we link a slower heart rate with better fitness. After all, some highly trained athletes have heart rates that run in the low 50s and even high 40s. Yet there’s another reason to rethink the current idea that a heart rate of 100 is normal. According to a number of studies, resting heart rates above 80 are linked with earlier mortality.

What’s Your Resting Heart Rate?

A number of factors can speed up or slow down your resting heart rate. For example, if you smoke cigarettes, the nicotine speeds up the activity of your heart. Caffeine, stress, fever, dehydration, and alcohol can too. If you have certain health problems, such as an overactive thyroid or anemia, it can also increase the pace at which your heart beats. Even some medications can speed your heart rate up while others, such as certain blood pressure or heart medications, slow it down. So, to get your “true” resting heart rate, you have to make sure these factors aren’t artificially speeding up or slowing your heart.

However, if you check your heart rate several times a day and it’s at the high end of normal and these factors aren’t influencing the results, you have a high-normal resting heart rate. While not a disease or health condition in and of itself, it, based on research, it’s a risk factor for an early death. Here’s the good news. A new study presented at the World Congress of Cardiology and Cardiovascular Health Conference showed a simple lifestyle habit – exercise – can offset the risks of having a high-normal heart rate.

In this study, researchers looked at heart rate information, including electrocardiogram tracings, on more than 515,000 men and women over the age of 20. The participants had resting heart rates ranging from 40 to 150 beats per minute. About 25% of women and 20% of men had a heart rate at rest in the high-normal range – 80 to 99 beats per minute. After following the participants for 8 years, they found those with a resting heart in the high-normal range could expect, on average, a 5.1-year reduction in lifespan for women and 5.6 years for men. That’s significant!

Exercise, Exercise, Exercise

Fortunately, if you fall into this category, there’s something you can do about it. Based on this study, exercise mitigates the risk of having a faster heart rate. Among men and women who were active, their lifespan was increased by a little over 5 years, thereby compensating for the impact of having a higher resting heart rate. To get the benefits, you don’t have to do strenuous exercise or spend long periods of time working out. As a Lancet study showed in 2011, even brisk walking for 30 minutes a day extends life by an average of four years.

How Exercise Increases Longevity

If you do aerobic exercise, you’re probably aware that it can slow your resting heart rate by a few beats per minute to as much as 20 beats per minute. That’s because, in response to exercise, your heart becomes more efficient at pumping blood. Its stroke volume or the volume of blood it pumps with each beat goes up. As a result, your heart doesn’t have to beat as many times per minute to deliver oxygen to tissues. That’s one of the perks of aerobic exercise and it partially explains how it increases longevity. Other ways exercise increases longevity is by lowering blood pressure, by reducing the risk of obesity, by improving blood lipids, and by boosting insulin sensitivity. As you can see, exercise is a natural prescription for heart health.

Recovery Heart Rate

Another indicator of how healthy your heart is how quickly your heart rate drops after a bout of exercise. To measure your own heart rate recovery, do a minute of aerobic exercise – jog in place, do jumping jacks, belt out some burpees, or jump rope. After a minute is up, check your heart rate. Rest for one minute. Then recheck your heart rate. If it’s dropped 12 beats per minute or less between the first check and the second, you have a slow heart rate recovery.

When doing this measurement, make sure you’re well hydrated since even mild dehydration can keep your heart rate from recovering as quickly. Also, be aware that certain medications can affect the results. Ask your doctor if you’re taking any meds that can affect your heart rate.

Why is a slow heart rate recovery significant? Like a high-normal resting heart rate, studies have linked it with a greater risk of mortality. A healthy heart slows down relatively quickly after exercise. The good news is this. Aerobic exercise mitigates the risk of having a high-normal heart rate, studies show you can improve your recovery heart rate and lower your risk of an early death through regular aerobic training.

Unfortunately, as the CDC points out, only about 20% of adults get the recommended amount of exercise, which is 2.5 hours of moderate-intensity exercise weekly or 1 hour and 15 minutes weekly of vigorous exercise combined with resistance training to preserve muscle size and strength. Not everyone is taking advantage of the heart health benefits that exercise offers – and that’s unfortunate.

The Bottom Line

Your resting heart rate and how quickly your heart rate drops after exercise says something about your risk of mortality. Fortunately, aerobic exercise can mitigate this effect and you get the other benefits exercise as well.

References:

Medscape.com. “Mortality Rises with High-Normal Heart Rate, but Exercise Limits Effect”

European Journal of Preventive Cardiology April 2012 vol. 19 no. 2 177-184.

Medscape Family Medicine. “Exercise Rehab Ups Survival in Abnormal Heart-Rate Recovery”

Circulation.2001; 104: 1911-1916.

CBS News. “CDC: 80 percent of American adults don’t get recommended exercise”