UNC Health Talk

For the Best Workouts, Know Your Target Heart Rate

We know exercise is good for us and has been shown to have many mental and physical health benefits, including burning calories to help lose weight. If your goals for exercise include weight loss, how do you know if you’re doing too much or not enough? One way is to monitor your heart rate, which is the number of times your heart beats per minute whether you are at rest watching TV or hard at work climbing a mountain.

Although a normal resting heart rate can range from 60 to 100 beats per minute, UNC cardiologist Christopher Kelly, MD, says a resting rate of 60 to 85 is typically the norm.

“The truth is that for most people, a normal resting heart rate is probably 85 or less,” Dr. Kelly says. “Having a heart rate of 99 when you’re sitting, resting and minding your own business, although technically defined as normal, is really not.”

How to Measure Your Target Heart Rate

You can take your heart rate manually: Find your pulse on the inside of your wrist or your neck using the tips of your first two fingers on the opposite hand. Count the beats for 30 seconds and multiply by two to find your beats per minute.

Of course, technology can help, too. Wearable activity tracker devices such as a Fitbit or Apple Watch have gained in popularity in the past decade and can help you monitor your heart rate during exercise and rest.

Hitting Your Target Heart Rate

So what should your heart rate be when working out? The answer is—it depends.

“When you exercise, your heart rate can go up quite a bit, and the maximum that we typically see is around 220 minus your age,” Dr. Kelly says. “As you get older, your ability for your heart rate to increase goes down a little bit. So 220 minus your age is approximately the maximum heart rate that you should achieve with exercise—plus or minus a few.”

So while it’s completely normal for a 20-year-old who does a high-intensity workout class to hit a heart rate of around 200 or even a little higher, it is not normal for a 70-year-old.

A normal target heart rate range for weight loss during moderate intensity activities, such as jogging or hiking a steep hill, is about 50 to 70 percent of your maximum heart rate. During vigorous physical activity, such as a spinning class or running a race, it’s about 70 to 85 percent of your maximum.

So if you’re 45 years old and your maximum rate is about 175, you might reach 122 beats per minute while jogging and 148 beats while running as fast as you can.

If your heart rate is too high, slow down. If it’s too low and you don’t feel dizzy, out of breath or lightheaded, you may want to push yourself to exercise a little harder, especially if you’re trying to lose weight.

Keep in mind, if you’re just beginning, aim for the lower range of your target zone, which is about 50 percent, and build up from there. If you keep at it, you’ll be able to exercise comfortably at up to 85 percent of your maximum heart rate.

Other Factors That Increase Your Heart Rate

In addition to exercise, there are other things that can increase your heart rate, including

stress, uncontrolled anxiety and poor sleep habits. These will all increase your adrenaline levels and your resting heart rate. Drinking caffeine and alcohol also will increase your resting heart rate.

Some medications or medical conditions, such as hyperthyroidism or anemia, can speed up your heart rate, and this means you may have a lower maximum heart rate and target heart rate zone.

Heart failure also can cause an abnormally elevated resting heart rate.

“If the heart is not pumping as much blood each time it contracts for a variety of reasons, it will compensate for that fact by getting faster so that the total overall blood being pumped per minute is the same,” Dr. Kelly says. “If each pump yields less blood, then it’ll just pump faster so that the total amount of blood being pumped doesn’t change.”

If you have a heart condition or take medication for anemia or hyperthyroidism, ask your healthcare provider what your heart rate should be.


Need a cardiologist? Find one near you.

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