Calculating Your Target Heart Rate

Your fitness routine has likely changed with current circumstances. The pandemic year—with gyms closed and stress levels high—affected us in multiple ways. As we get back into an exercise regime, it’s important to do so with awareness. That includes knowing your actual target heart rate (THR) zone and using that zone for a safe, effective workout—whether you’re going out for a run or heading back to a studio for the first time.

Monitoring your heart rate during an exercise session is a concrete, numbers-don’t-lie way to sneak a peek inside your body to find out what exercise intensity is right for you. In fact, it may be the piece of data that finally convinces you not to push too aggressively during your cardio routine—or not take it so easy that you barely get your heart rate up. Not everyone is meant to work out the same way and figuring out your target heart rate zone can give you a clearer sense of just how hard you should push yourself to improve your health and fitness.

Heart Rate and Your Health

During aerobic exercise, your heart, lungs, and circulatory system are called on to deliver oxygen and nutrients to the muscles you’re engaging. Your heart rate is one way to measure just how hard your body is working to do all of that.

“When you regularly perform aerobic exercise at a challenging intensity, elevating your heart rate, you reduce your risk of obesity, heart disease, type 2 diabetes, and other health conditions. Even your brain health can improve,” explains Heather Giordano, MS, Performance Scientist at Canyon Ranch Lenox.

Acknowledging the vast benefits of engaging in regular aerobic has led the American College of Sports Medicine and the Centers of Disease Control to issue landmark papers recommending aerobic activity for all healthy adults. Considering this, you may think that working out harder is always better. But reaching your maximum heart rate — the greatest number of beats per minute your heart can possibly achieve during exercise — requires an all-out effort that is extremely uncomfortable and impossible to maintain; even the most highly trained athletes can only maintain this intensity for a few minutes at a time. Knowing your THR zone helps you navigate your workout safely and effectively.

How to Calculate Your Target Heart Rate

Your target heart rate (THR zone) is 70 to 85 percent of your maximum heart rate, which must be determined before you can zero in on your target range.

You may have seen simple formulas for determining maximum heart rate, or even charts that give a suggested THR based on gender and age. While these may seem somewhat helpful for general reference, they can be very inaccurate. Because both options serve the masses and use age as their only reference point, they can be off by as much as 30 beats per minute in estimating maximum heart rate. That’s why you’ll need the help of your exercise physiologist or doctor to determine your THR — the intricacies of the human body simply vary too much from person to person to use one-size-fits-all formulas.

Below are the tests your health professional, like the ones at Canyon Ranch, might recommend to help determine your unique number:

Submaximal Exercise Test: A heart-rate monitor is placed on you while exercising on your preferred cardio machine, like a treadmill, elliptical, or stationary bike. Your Exercise Physiologist increases the machine’s intensity every two minutes for about 15 minutes total. By observing the feedback on your heart-rate monitor and checking in on your exertion level — your breathing rate, whether you can talk without huffing and puffing, your comments on how you’re feeling — as you go, he can gauge when you likely reached 70 percent and 85 percent of your maximum heart rate. And this is your target heart rate zone.

VO2 Maximum Test: This test is the gold standard for determining your target heart rate. While on your choice of a treadmill, elliptical, or stationary bike, you wear a heart-rate monitor and a portable device called a metabolic analyzer, which takes samples of your breath to measure how much oxygen you consume and how much carbon dioxide you expel as you work at incrementally more challenging workloads. Your Exercise Physiologist will stop the test once you have had enough — ideally when you are at 90 to 95 percent of your maximum effort. The test also measures your VO2 maximum, your anaerobic threshold, and how many calories you burn at any given heart rate.

Cardiovascular Stress Test: Your cardiologist usually performs this test when it needs to be determined if your heart can safely tolerate aerobic exercise. Twelve electrodes are placed in specific positions on your chest. You then exercise while your doctor watches the electrocardiogram (EKG), which traces how your heart beats, and takes your blood pressure every two minutes. The test also tracks your heart rate, which your physician will use to estimate your maximum heart rate, and then determine your THR. This test is typically performed on men over 45 and women over 55 who have never had a stress test or are at risk for cardiovascular disease or heart attack.

Using Your Target Heart Rate

“A portion of your workout — usually your warm-up and cool-down — should be spent below your THR, or at about 50 to 65 percent of your maximum heart rate,” adds Giordano. And, you guessed it: part of your workout should be spent in your target heart-rate zone, or about 70 to 85 percent of your maximum heart rate, according to recommendations from the ACSM.

Your Exercise Physiologist can help you determine how long to spend in each range in your various workouts, depending on your fitness level and goals.

As a general rule, try to stay within your THR, or the 70 to 85 percent range, for most of your workout so that you can reap the benefits of your aerobic activity. If you stay at anything lower than 60 percent range for too long, you’re probably not challenging yourself adequately. Increasing your pace, amping up your resistance, and/or raising the incline, can help keep you in the zone.

“For daily exercise, aim to be at your THR for 30 minutes for most days of the week,” she says “The ACSM and CDC recommend that healthy adults strive for 150 minutes per week in their THR zone.” During interval training you should attempt to tease the 80 to 90 percent of your maximum heart rate zone during your harder efforts and ensure that during the recovery periods you recover to 65 to 75 percent of maximum heart rate. If you’re a beginner, start at 65 to 70 percent of your maximum heart rate and gradually increase the intensity. If you find it challenging to reach that number at first, give yourself points for exercising and remember that, with time, your stamina will improve.

Whether you’re a beginner or an advanced exerciser, you may find the constant feedback you get by gauging your effort with a heart rate monitor — a tool that you can purchase online or at sporting goods store — to be both motivating and enlightening. A strap fits snugly around your chest and picks up the internal electrical signal your body uses to make your heartbeat, which is then transmitted and displayed on a watch-like device and/or the console of your exercise machine.

You can then view your heart rate data in real time on your watch or on the console of the cardio machine on which you’re exercising. Some cardio machines are equipped with hand sensors that you can grip tightly for a heart rate measurement. You can use them, but just keep in mind that their readings tend to be inaccurate.

“Before you begin any exercise program, discuss it with your physician. And be cautious if you have a heart condition and/or take a beta-blocker medication,” says Giordano. It will lower your heart rate whether you are at rest or exercising, which means that your maximum heart rate and target heart rate zone will be significantly lower than charts will predict. Do not try to achieve chart-predicted heart rates. “Remember, more is not necessarily better,” she points out. If your workout feels uncomfortably strenuous, regardless of your heart rate, slow down.

Giordano recommends that you finish out your workout with a brief cool down—and gradually decelerate to an easy pace, until your breathing rate has slowed to near normal. End with a few minutes of gentle stretching to keep muscles limber.

This article was originally published on July 17, 2021, and has been updated as of the above date.