I won't, I promised my editor, write about running for a while -- and certainly not about the Marine Corps Marathon -- but this isn't about that.

It's about breaking out of the body trap, or is it the mind trap? You know what I'm talking about. The trap that makes you light up a cigarette when you see a biker, runner, or walker go by, to distance yourself even more from them. The trap that makes you head for the ice cream when everything in your closet has, mysteriously, shrunk two sizes.

It's the trap that makes your eyes go glittery and cold -- hostile -- if anyone mentions that exercise might make you feel good. The trap that makes you look at other people moving around and shrug, sure, that's okay for them, but not for me. Of course, I wouldn't mind having my cheeks a little rosier and my eyes a little brighter, and maybe I would have more energy and be able to think a little bit better, but no, I'm just not the athletic type. Never have been.

It's the trap that is keeping you from yourself -- from the best that you can be -- and making you a stranger in your own skin.

Who am I to say all these things? The nerve. And don't you wish I'd be quiet? I can't be, because I see you everywhere, and I know how it feels to be an alien in your own skin, and the fatter you get and the more you smoke, the bigger the canyon between you and the world, the bigger the moat between you and yourself.

I recognize you because I've been in that trap of smoking, eating, thinking and drinking too much, doing everything too much except exercising too much, and that was a word -- conjuring up dumbbells and sit-ups -- that I hated too much.

I know how smug all this is beginning to sound.

Cut. Remember? I was your typical 50-year-old Washington female, sedentary and tired all the time. I started walking around a school track -- once was more than enough at first -- and kept adding more and more laps until the legs decided to start running one day. (This is not a column about running.)

One summer I went to the beach with a good friend. I told her I liked running and she might want to try it. She said no, I hate running; it's boring, and it makes my side ache.

But one morning she was out there with the rest of us, and then another day and another day and when the week was over, there was a new light in her eye and a different set to her jaw, as if her horizon had been extended and she was peering further off in the distance. And of course, my friend -- who's no spring chicken either, although she's springier than this chicken -- told all of us that she still hated running.

To make a long story a little shorter, she kept at it, and I kept at it, and we'd compare notes about how it was all going. We'd challenge each other over the phone -- 900 miles apart sometimes -- and talk about what it was like in the rain or snow or heat and how, isn't it amazing, we've lost weight without even dieting. And isn't it nice that our metabolism keeps going even after we're through. And have you noticed a lot more energy?

We talked about how cravings for junk food gradually disappear because when you get out there on the road, your body tells you in no uncertain terms what works, and what doesn't. What fuels, and what doesn't. If you've had too much fatty pizza the night before, you just don't feel right. Period. That also goes for too many chocolate-chip cookies. And after awhile, you don't even want all that sugar. You crave feeling good more.

And we laughed, as in, "My God, can you believe it?" We, who used to smoke at least two packs of cigarettes a day, who thought people who exercised were sort of strange. ... We who a few years ago would have had you put away if you told us we'd be doing this, were now getting up at 5 a.m. sometimes to get in our workout. That hour had become as critical to our well-being as eating and sleeping -- and when do you ever not find time for them?

We talked about how if a couple of days went by and we hadn't exercised we could feel the adrenaline building up, and one of us would say something like, "I've got to get out there and get rid of that stuff." We were, of course, naturally releasing stress, which in the past we had just pushed back inside with cigarettes, food, wine, beer and frenzied bursts of rushing about.

I could tell in her voice, and she in mine, when one of us needed a run. The non-exercised voice just sounded more tentative and equivocal; the exercised one, tougher and grounded. I almost missed a deadline once because my mind had locked; she suggested I use one of the remaining three hours to run; my mind unlocked and I made the deadline.

Sometimes I'd tell her I was going for a run to find out what I was thinking about. She knew what I meant.

A lot of younger women, of course, know about these things. Or at least more than those of us over age 40 do. We celebrated the little bulges appearing in our legs and arms, we who had grown up at a time when muscles were considered inappropriate for women.

We conspired on more and more challenging goals, and when we'd finish, we'd shout and give each other five and leap about like two little kids. We were thrilled. Remember when we couldn't do one mile? Remember when you hated running?

We were amazed, flabbergasted, astounded at our bodies' capabilities. All that power -- an unknown quantity -- lying dormant all this time ... my body did that?

And we talked about the process -- the goal-setting, the training, the way there -- being as important as the arrival. The journey as much fun, as satisfying and as significant as the destination.

We could have been biking, or swimming, or walking, but we were getting somewhere, and we knew it. And getting somewhere as an adult -- learning to truly inhabit your body, the whole fantastic estate rather than just a few rooms -- is an extraordinary experience.

So start with a few goals now -- maybe one-half mile walking, two miles biking, two laps across the pool, whatever exercise you like, or could learn to like -- and keep stretching those goals. You'll be amazed at where you can go in six weeks, and astounded over what can happen to body and mind in a year of regular exercise.

And if you have a good friend/husband/wife/lover who wants to set off on that odyssey with you, all the better.

My friend and I? We did the Marine Corps Marathon the other day and now are trying to decide what to reach for next.

(This is not a column about running.)