When exercising, it’s important to elevate your heart rate enough to get a good workout, while not too high as to place unnecessary stress on the heart. The American College of Sports Medicine recommends keeping your heart rate below 85% of your maximum heart rate, which is calculated by subtracting your age from the number 220. For example, a 50-year-old man should keep their heart rate under 144.5 beats per minute. WebMD, November 2022