Aerobic fitness: Target heart rate zone

The target heart rate zone is an increase in your heart rate — 50% to 85% of the maximum heart rate for your age — great enough to give your heart and lungs a good workout. Aim for 50% to 70% when you do moderately intense activities and 70% to 85% when you do vigorous activities.

You can use the target heart rate zone as a guide for making sure your exercise is intense enough. If you're not reaching your target zone, you may need to increase the intensity. If you're achieving a target rate in the lower end of the target rate zone, you can set goals for gradually increasing your target.

If you already exercise regularly, you can stop to check your heart rate sometimes during an aerobic workout. If you don't exercise regularly, you can do a simple test by checking your heart rate after a brisk 10-minute walk.