I mproving your physical fitness needn't require an arduous exercise regimen. And you certainly don't have to go to a gym, wear special clothes and sweat a lot.

But if you want to improve your health and fitness, you must increase your physical activity. This can be done gradually, at home or at work or with the help of a professional program. Your goal should be to change your behavior, not wear yourself out.

Burning 200 to 300 more calories a day through moderate-intensity exercise lowers the risk of heart disease, stroke, diabetes and some cancers, and other conditions related to stress or being overweight. You'll also increase fitness, which will give you more energy and lead to greater enjoyment of life.

ACTIVITIES FOR HEALTH

Some of the most effective ways to boost physical activity often are overlooked...

Increase the number of steps you take each day. That alone will go a long way toward burning calories and exercising muscles.

Helpful: Use a pedometer to record the number of steps you take. My favorite is the DIGI-WALKER, which accurately records steps you take. It is sold at sporting-goods stores and is also available directly from New Lifestyles, www.new-lifestyles.com. Cost: From $29.95.

Most people over age 50 who work in sedentary jobs and don't exercise regularly take about 2,000 to 4,000 steps a day. It's easy to increase this.

When you go to the mall, for instance, don't drive around until you find a parking place next to the door. Park in the first available space, and walk to the entrance. You'll increase the number of steps you take and often save time in the long run.

Before you take the car out for a short errand, think about walking. You often will be delighted at how much you see in the neighborhood. If you take public transportation, getting off one stop early can be similarly enjoyable and will add steps to your trip as well.

Stand instead of sit. Standing burns more calories than sitting, which is what many people do for 12 hours a day.

When you talk on the phone, get in the habit of standing. And at least sit up when you watch television instead of stretching out on a sofa. Sitting burns more calories than lying down.

Move around. Even slow walking burns twice as many calories per minute as sitting. If you have a mobile phone or a phone with a long cord, don't merely stand each time you have a conversation. Instead, walk around as you talk.

Do household chores. Catch up on your gardening. Or repaint a wall, repair the kitchen cabinet, hang new pictures or rearrange the furniture.

Take up a sport or physical activity. Try one that always interested you or one you once enjoyed but gave up as your responsibilities grew.

Examples: Bicycling, tennis, swimming, bowling, golf, running.

Call local clubs in your area. You may be surprised to find out how many people over age 50 are resuming a sport or taking it up for the first time.

KEEP ON TRACK

Increasing your physical activity, even gradually, isn't always easy. The big problem is reversing the long-established behavior of avoiding unnecessary exertion. Helpful...

Set goals. Aim low at first. When you reach your first objective, set the next goal slightly higher. The satisfaction of reaching a goal will inspire you to go on to the next.

On the other hand, nothing is more discouraging than setting a high goal and then failing to meet it. Examples of reasonable goals...

If a pedometer shows that you take about 3,000 steps a day, set a goal for increasing the number by 500 a week until your daily rate is in the 8,000 to 10,000 range.

If your goal is to lose 30 pounds, set a goal of five pounds a month.

Monitor your progress. Recording physical activities in a diary can help develop momentum for reaching your goals. Keep the entries short so the diary itself doesn't become a chore. Just record each day's physical activity, and make a note of whether you met your goals.

If you use a pedometer, record the number of steps you take each day. It also helps to estimate how many hours a day you sit and how many you spend moving around. Over a period of several weeks, the log should show a decrease in the amount of time spent sitting and an increase in moving around.

Join a group. Though you can easily increase your physical activity without joining a health or fitness club, being a member of a group offers two major advantages -- you'll have access to a professional trainer and support from fellow members.

Look for a group that helps members achieve a modest -- but steady -- increase in physical activity.

Human Kinetics, a publisher with which I'm affiliated, is in the process of establishing Active Living fitness centers at health clubs, hospitals, work sites and Ys throughout the country. These centers teach changes in lifestyle, encourage goal-setting and establish support systems to help people stay physically active. Those are the qualities to look for in any activity group.

Information: www.activeliving.info.

Gather support. Research on physical activity shows that people with support from friends or family members are far more likely to succeed than those who try to do it on their own. Support can be especially critical during the early stages of a fitness program. Recommended...

When you decide to increase your physical activity, tell two or three friends about your goals, and ask them to help you. Choose these people on the basis of how supportive they've been in the past -- those who will phone you periodically to check on your progress or to encourage you to reach difficult goals... or better still, those who will go for a walk with you at lunchtime.

If someone you hoped would support you doesn't follow through, immediately enlist the support of someone else.

When you evaluate fitness programs, ask what type of support they offer. The best programs encourage participants to support one another after class and to find support among other friends.

Safety: Moderate-intensity lifestyle activities discussed here are safe. You are just doing more of what you normally do. If you have a history of heart problems, osteoporosis or other conditions that could interfere with physical activity, check with your doctor. If you experience worrisome symptoms during exercise, such as pressure in your chest or extreme breathlessness with mild exertion, stop your exercise and check with your doctor.

Information: Visit www.americanheart.org.