The chart below from the AHA outlines the various target heart rate zones and average maximum heart rates based on age. The AHA notes that your maximum heart rate is often 220 minus your age.

PRINTED ON TREADMILLS and exercise bikes in gyms around the world is a simple method for estimating the maximum rate at which your heart should safely beat, in beats per minute: 220 minus your age.

Runners, cyclists and gym-goers with wearable fitness trackers are no doubt familiar with the five "heart rate" zones. Ranging from low to very high intensity, these zones are calculated as ...