Understanding exercise intensity

When you're doing aerobic activity, such as walking or biking, exercise intensity correlates with how hard the activity feels to you. Exercise intensity is also shown in your breathing and heart rate, whether you're sweating, and how tired your muscles feel.

There are two basic ways to measure exercise intensity:

• How you feel. Exercise intensity is a subjective measure of how hard physical activity feels to you while you're doing it — your perceived exertion. Your perceived exertion level may be different from what someone else feels doing the same exercise. For example, what feels to you like a hard run can feel like an easy workout to someone who's more fit.
• Your heart rate. Your heart rate offers a more objective look at exercise intensity. In general, the higher your heart rate during physical activity, the higher the exercise intensity.

Perceived exertion may not always be similar to your heart rate level, and it depends on the individual. But it can be a general guide to measure your exertion level. If you think you're working hard, your heart rate is probably higher than usual.

You can use either way of gauging exercise intensity. If you like technology, you can check your heart rate with an activity tracker that includes a heart rate monitor. If you feel you're in tune with your body and your exertion level, you'll likely do fine without a monitor.