Sam S. is 61 years old and lives in Atlanta, Georgia. His main forms of exercise are running and using exercise machines at the local health club. In the interview below, he answers questions about how he finds the motivation to stay active.

First, can you describe your typical exercise routine?

I run 10 miles three times a week. Each of those runs takes about 90 minutes.

On alternating days, I work out at the local health club -- I try to work every muscle in my body, going from one weight machine to the next. I'm just trying to stay toned and stretched; I'm not trying to bulk up. After the weight machines, I spend about 20 minutes on an elliptical machine. The elliptical gives me a workout like running without the impact of running, which is why I do it every other day. I stay at the health club for about an hour, sometimes a little more.

One day a week I rest.

When did you begin to exercise regularly?

I was in track during high school. I knew that I felt better when running, so I started recreational running in 1964 to stay in shape, after I got out of the Navy. I suppose I have exercised off and on for most of my life.

However, I've been on my current exercise plan for about 6 years. I consider what I do now "smart running." I used to run 6 - 7 days a week, and that's not the best way to exercise. Running every day puts too much wear and tear on your joints, and the older you get, the more important it is that you don't do that. Furthermore, I learned that you actually train more competitively if you only run every other day.

Did you have any periods where you stopped exercising?

There were periods when I didn't run very often because I traveled a lot in my job. Once I stopped exercising, it was always very hard to get back into it. You get into doldrums where you just don't feel like getting into exercising again. That's one of the reasons I don't ever stop now -- I know how hard it is to get going again. An exercise program is as much mental as it is physical. Physically, I've never had any trouble getting back into it.

I was always able to start exercising again because of the challenge it presents -- I always wanted to prove to myself I could do it. I have a strong sense of competition and I run a lot of local races. In fact, I started running marathons for that very reason -- to see if I could do it.

If exercise were just physical, I think most people would do it. It's the mental aspect that is the hard part. You need to find your motivation. Dr Sheehan, who was big in the running community, said something like, "It's not a miracle that I finished a marathon, it's a miracle I started it."

Just like me, though, I think anyone can get into exercising if they commit to it. It's not a matter of wanting to exercise -- it's a matter of doing it. There's no getting around that.

What motivates you to do it? What keeps you going?

Exercise makes me feel good. I feel tremendous accomplishment when I prove to myself I can meet speed or distance goals. If you want to prove you can succeed at something, which most men and women probably have the urge to do, then you have to find a challenge. Running is a great way to push yourself and explore your limits. You realize that the first time you run a race.

Also, I know how hard it is to get going again if I ever stop. Momentum, once you have it, is fairly easy to maintain. That's good for anyone starting out to know -- that once you get past the beginning and form exercise as a habit, it's pretty easy.

What supports you?

When you are running the race, you can usually find someone running a little faster than you, and it helps pace you and push you. In a way, the others in the race pull you along -- it is the sheer energy of it. And you get a little thrill passing someone you've been trying to catch up to.

A running partner helps a lot, and on long runs, it's a necessity. At least for me. Again, it's the mental part that is hard, because there is no physical difference between running by yourself and running with someone. Along the same lines, running is a hobby that you can enjoy with people.

When you just don't feel like exercising, how do you get past that feeling?

I do all my exercising first thing in the morning, and I never feel like getting out of bed at 5:30 in the morning. But once my feet are on the floor, I'm good to go. The reason I can get out of bed is because it's simply a habit now, as strong as brushing my teeth or anything else. Once it's a habit, that's when you've got it made. If you lay there too long, you'll just talk yourself out of it. No matter what your exercise plan is, if you lay around thinking about it, you'll talk yourself out of it. So I just wake up and do it, and within a matter of seconds -- once I'm moving -- it's no problem.

How do you fit regular exercise into your schedule?

By doing it first thing, early in the morning. That's the only way I can fit it into my own personal schedule. Everyone is different, I'm sure.

If it rains or your schedule is disrupted, do you have any backup plans?

If it's raining, I go to the health club and run on the treadmill. Of course, I am human, and sometimes I turn over and go back to sleep, but I try not to do that often. If I have a race coming up, I guarantee I'll get out of bed and go do it. Races are good for motivation because they set a definite goal and a date that goal has to be reached.

I should point out that most people who run races are pretty average people who do it for the fun and to stay in shape. I don't want to convey that you have to be really competitive to enjoy races. There are hundreds of small, local races all over the country all year round. The crowds always cheer everyone on, even the people at the end. For most people, winning doesn't mean coming in first, it means getting off the sofa and training for the race in the first place. The mood created at a race is a spirit of fitness, not coming in first. Most of the people who go to races are just trying to beat their own personal time goals.

How do you reward yourself for achieving your fitness goals?

After 20 miles, I reward myself by sitting down. No seriously, the reward is just the physical and mental pleasure I get, the way I feel very peaceful, calmer, able to face the rigors of the day much, much easier. When I get out of bed and go straight to work, my day is a lot rougher. I am much happier when I am exercising and training for races than when I'm not. I feel better physically. It's a very positive addiction, if you will.

It's also the sense of accomplishment. I certainly don't run 20 miles for the T-shirt, but those T-shirts are nice to collect and they do symbolize your dedication to exercise.

You feel really pumped that last half mile when everyone is on the sidelines cheering. Especially in a marathon, when you are almost done and the crowd is cheering, no matter who you are or how well you're doing. When you're by yourself on the road and everyone is encouraging you on -- well, you almost think you're doing something! It's your 15 minutes of fame. People who go watch races are always extremely supportive. It's not about winning so much as being out there doing it.

What tips or advice do you have for others?

Keep pushing yourself to exercise until it becomes as natural as brushing your teeth. Then it becomes something you simply do every day, not something you do if you have time. That's why I do it in the morning, because schedule conflicts are less likely to come up. Wanting to do it is not enough; you have to make yourself do it.

The best thing you can keep in mind in running is to know when enough is enough, when to rest, when to stop training. If you have doubts, you have probably run enough.

Don't try to do too much as a beginner and hurt yourself or burn out. Finally, liberal use of stretching after you exercise.