An expert panel from the American Heart Association and the American College of Sports Medicine issued guidelines in 1995 stressing the importance of exercise in overall health. Apparently we didn’t get the message because less than half of all Americans exercise. So the guidelines have been simplified and reissued. Everyone needs two type of exercise for a healthy life: aerobic exercise and strength training.

AEROBIC EXERCISE

• Walk briskly for 30 minutes five days a week, or
• Jog for 20 minutes three days a week, or
• Mix walking and running. For example: walk briskly for 30 minutes twice a week and jog 20 minutes twice a week.
• You can break up these activities throughout the day but the segments should be no less than 10 minutes.
• You can substitute other moderate-intensity activities for walking, but you can't count low-level daily activities -- such as walking from the parking lot to the grocery store or taking out the trash -- as exercise.
• You can substitute other vigorous-intensity activities for running, as long as your heart rate increases noticeably and you start to breathe fast.

STRENGTH TRAINING
This means activities such as weight lifting. These exercises should result in "substantial fatigue after eight to 12 repetitions of each exercise," the guidelines state. Strength training twice a week is the minimum required for health. More training is needed to improve fitness, reduce risk for disease, and/or prevent weight gain.

The new guidelines appear in the August issue of the ACSM journal Medicine & Science in Sports & Exercise.