Knowing your heart rate zones can help you measure and improve your fitness by understanding and applying these principles.

• Your heart rate is a good measure of exercise intensity.

• Training in certain heart rate zones can help you improve cardiovascular capacity and strength.

If you know your maximum heart rate, you can use the table (Heart Rate Zone Calculations) to determine the best heart rate zone for your fitness objectives.

If you do not know your maximum heart rate, use one of the calculators available on the Internet. Some gyms and health centers can provide a test that measures maximum heart rate. The default maximum heart rate is 220 minus your age.