Exercise and Fitness

How much exercise is enough? Two recent studies may have the answer. A review of the 25-year exercise history of almost 17,000 Harvard alumni revealed that those who were more active lived up to two years longer than their couch potato counterparts. Health improvements resulted from burning even 500 calories per week through exercise. However, burning 2,000 calories provided the best health benefits.

In another study, 13,000 men and women were divided into five fitness groups. The least-fit group had, by far, the highest number of deaths. But surprisingly, the most dramatic drop in death rate occurred in the second-least-fit group. This group exercised moderately - the equivalent of 30 to 60 minutes of walking per day - and burned a weekly total of 1,000 to 2,000 calories.

These studies dispel the idea that activity has to be intensely aerobic (meaning it makes your heart and lungs work harder to meet your muscles' demand for oxygen) to produce a health benefit. There is convincing evidence that lower-intensity activities like walking, gardening and golfing have very favorable health benefits. Ultimately, doing any activities that use up to 2,000 calories per week is a healthy goal. At the very least, get in at least 30 minutes of moderate exercise three times a week.

For nearly everyone, the risks of not exercising far outweigh the risks of exercise. Still, for those with existing chronic illness such as diabetes, heart disease or high blood pressure, consult your physician before you start an exercise program.

You don't have to endure the rigors of a runner who is training for a marathon. Competitive athletes often suffer sports injuries, but moderate activity rarely leads to injury if you build up slowly. In fact, intense exercise - the kind that leads to injuries related to wear and tear on the joints - is simply not necessary to achieve long-term health benefits.

How to Get Started

• Get off to a slow start. If you are just beginning, 30 minutes of walking three times a week is plenty. Move slowly toward a daily routine of 30 minutes of activities you enjoy. But increase your activity only when you feel your present level is getting too easy.
• Keep a diary of your activity. As your entries build, so will your commitment.
• Try a variety of activities to keep exercise fresh and interesting.
• Exercise at the same time every day. If you can't lock into a regular time, then schedule your exercise in advance - as an appointment to keep with yourself. There is some evidence that people are more successful at sticking with a morning routine.
• Join a club or start a regular routine with friends to add a social element to your activity.

There is no secret formula for deciding how much exercise is enough or which types of activities are best. In general, when it comes to activity, the more, the better.

Exercise and Calories

The following is a list of common activities and the average number of calories a 150-pound person will burn during an hour of the activity:

Exercise/Activities	Calories Burned Per Hour
Biking (5 1/2 mph)	210
Walking (2 1/2 mph)	210
Gardening	210
Golf	250
Swimming	300
Walking (4 mph)	300
Tennis, doubles	300
Biking (10 mph)	415
Tennis, singles	420
Aerobics	445
Jogging	585
Running (8 1/2 mph)	700
Cross-country skiing	900