Reap the rewards of exercise intensity
You'll get the most from your workouts if you're training at the proper exercise intensity for your health and fitness goals. If you don't feel like you're working out hard enough or your heart rate is too low, pick up the pace. If you're worried that you're pushing yourself too hard or your heart rate is too high, back off a bit.
Before starting a vigorous exercise program, you may want to talk with a member of your health care team, who may suggest that you have certain tests first. This may be the case for people who have diabetes or more than one risk factor for heart disease, and for men over age 45 and women over age 55.