Ask the Expert: What Should My Heart Rate Be During Exercise?

Aim for this heart rate to burn the most fat during your workouts.

You may have been told you should be exercising moderately for 150 minutes per week or vigorously for 75 minutes per week, but you probably haven’t been told how to exercise. What does “moderate” and “vigorous” mean? The answer lies in your heart rate. We sat down with James A.M. Smith, DO, a cardiologist with Wesley Medical Center in Wichita, Kansas to demystify heart rate and exercise.  

Max and Target Heart Rates
To get a handle on heart rate, the first thing you’ll need to do is some simple math. Take your age and subtract it from 220. That’s an estimation of your maximum heart rate. There are other ways to find this number, but this method is the easiest. According to the calculation, a 50-year-old, for example, would have a maximum heart rate of about 170.

Your target heart rate during exercise is a percentage of your maximum heart rate. Dr. Smith recommends a target heart rate of about 75%. For a 50-year-old person, that would be about 120 beats per minute. No need to take your pulse, says Smith; just go by how you’re feeling. “You should be breathing heavily and have a light sweat going,” he explains.

Why 75%?
A heart rate of about 75% of your maximum heart rate is a good target, says Smith, because you’re burning fat. “Above or below, you’re burning carbohydrates,” he says.

The body has three main sources of energy: carbohydrates, fat and protein. “Carbohydrates are basically the first to burn,” says Smith. At about 75% of your maximum heart rate, the ratio of fat to carbs burned is highest. Fat burning drops off the closer you get to your max heart rate.  

Exercise Recommendations
According to the Centers for Disease Control and Prevention (CDC), everyone should aim for 150 minutes per week of moderate cardiovascular exercise. Smith says the bare minimum is 30 minutes three times per week. “The heart is a muscle and we’re trying to condition that muscle to improve blood flow to the brain and the skeletal muscles,” says Smith.

The recommended 150 minutes of exercise can be reduced with interval training. Interval training—often called high intensity interval training (HIIT)--means working hard and seriously increasing your heart rate for a brief period, then dialing the energy back down for an active rest. For example, if you’re on an elliptical trainer, go all out for 15 or 30 seconds every quarter mile then reduce your speed until the next quarter mile.

“You’re creating hypermetabolic conditions,” says Smith. “You’re breathing fast, your heart is beating fast and the body is clearing waste products fast.” A 2015 meta-analysis of 50 studies found that HIIT can improve metabolic health, especially in people with or at risk of diabetes.  “For people who don’t have an hour to work out, you can accomplish a lot through interval training,” Smith said.  

Heart Health

Heart Health

Treat your heart right by eating healthy, staying active and managing your stress. Although some heart conditions are heredity, you can reduce your risk by keeping your cholesterol and blood pressure at healthy levels, avoiding to...

bacco products and losing some pounds if you are obese or overweight. A diet high in fiber, veggies and fruits is essential for a healthy heart. Vitamins and supplements, such as fish oil, may help reduce your cholesterol, which if too high can cause blockage in your arteries and lead to a heart attack. If you arteries are blocked, you may need a stent or cardiac angioplasty device to open your blood vessels, which can help prevent a heart attack. Because heart disease is the number one killer of adults in the U.S., taking care of your heart is essential for a long life. If you have a family history of heart disease, it is especially important for you to manage your hearts health.