Target heart rate is a guide to let a person know how hard to exercise to gain the most aerobic benefit. Being active within the target heart rate range helps a person not only keep the heart and lungs healthy but also raise or stay at his or her fitness level.

A person can take his or her pulse and then adjust the activity level to get within the target heart rate range. During exercise, a person's heart should be working hard enough for a healthy effect but not so hard that the heart is overworked.

A person’s age, resting heart rate, and activity level affect target heart rate. Younger people have higher target heart rates than older people. Active people have higher target heart rates than people who are not usually active.

Target heart rate is only a guide. Everyone is different, so during exercise it's important for people to pay attention to how they feel, how hard they breathe, how fast the heart beats, and how much they feel the exertion in their muscles.

Chronic health problems and certain heart medicines affect a person's target heart rate range.