These are the confessions of a five-miler.

That's five miles at a time on the Appalachian Trail, the 2,000-mile footpath that snakes along the mountains from Georgia to Maine.

I've been at it 15 years and at the rate I'm going I estimate I have only another 137 years to go. With some men it's little ships in bottles, or Superman comic books, or records of old radio shows. With me it's hiking the Appalachian Trail five miles at a time.

Sometimes, of course, the mileage is a little more, sometimes a little less. A two- dayer, with an overnight stay at one of the huts along the trail can maybe net 12 miles, a huge achievement in the life of a five-miler.

I enjoy the hiking, the mindless lifting up and putting down of one aching foot after another. And ahh, it feels so nice when you stop.

Yet I also enjoy the planning: the fixing of the route, the analysis of the elevations to be encountered, the accumulation of the food and other supplies.

There is also that great gift that knocking about in the outdoors provides: an intimate communion with nature. One achieves an understanding of nature that I, nutured as I was on city pavement, did not obtain as a child. For example, from the long drives to the trail at various times of the year I have developed a mental motion picture that shows the gradual greening and growth of wheat in fields throughout the mid-Atlantic region. Regrettably, since I don't hike during the worst of the summer heat, I've never seen the final blossoming when the wheat flares out in little flakes covered with pink sugar.

Those who knock off the trail in one three- month trek are in another game altogether. My hat -- perhaps I should say my boot -- is off to them. They have my greatest respect, particularly one Vietnam veteran I encountered somewhere in Virginia who had walked there from Maine. I was dumbfounded when he asked me where he was; he was doing the whole trail without a map.

Day-hiking the Appalachian Trail could also have another name: Search for the Second Car. Park the two cars at each terminus of your planned route and you can step off a heartwarming six or seven miles. Without the second car, you have to retrace your steps and be satisfied with an ignominious three or so new miles. Somehow, at whatever cost, you've got to find someone with a car to go with you. Thus, in addition to developing the country skills needed to cope with outdoor living, a dedicated hiker has to cultivate the urbane arts of diplomacy and cajolery in persuading the unwilling to do the unnecessary.

Why do it? Why the hassle, the pain, the impossible challenge. As every man probably does at one time in his life I concluded that in the true integration and maturation of the complete individual, that is, the id, the ego and the superego, lies in the disciplined, albeit subliminal, interface with the Logos of Time, not the least of all with its interstices.

Without that concept to sustain me I am convinced I could never have ccomplished what little I have.

Day-hiking on the Appalachian is relatively cheap as outdoor hobbies go. As a minimum I would recommend sturdy boots and a day pack, which together would probably run you less than $100. A parenthetical tip: leave a pair of slip-ons in the car for the drive back. Your feet will be grateful.

You'll also want the trail-club map covering the section you'll be hiking. They are available for a dollar or so in "outfitters" stores -- the ones that sell serious camping supplies -- such as Appalachian, Hudson Bay and Eddie Bauer.

Overnighting can kick the price up considerably when you start figuring in tents, sleeping bags, pads, stoves and so on. Even here a little imagination can help keep costs down. I have used a sturdy plastic sheet a painter would call a drop cloth and I call a tube tent. String a cord between two trees, drape the cloth over it and hold the bottom together with your equipment. The cloth you buy at a store will probably give you a lot more space than you need. If you have some extra time beforehand you might want to trim it back.

If the weather forecast is good your clothes will provide enough warmth and you can forget the sleeping bag. As for eating, the Boy's Scout Handbook has several ideas on getting a fire going and cooking with whatever materials are at hand.

A precautionary note: These suggestions are for short trips only when, if the weather turns nasty or other problems develop, you can bug out to your car fairly quickly. Longer forays need more elaborate preparations.

Other expenses are, of course, gas, park fees and highway tolls.

Perhaps the highest price I've paid as a part-time hiker has been in friends (the owners of those vital second cars). They don't think I notice them duck around the corner when they see me coming. They seem to lack the greatness of soul that would enable them to forgive and forget that I might have underestimated the distance of our last hike by a few miles.

In some cases I have been only to happy to find out early on that some people lack a certain depth of concentration, a seriousness of purpose. Some for example, have begged off on hikes because they want to work on their yard or because they have tickets to the Kennedy Center, whatever that is.

My two sons boys are of an age now where they can be trapped into joining me on some jaunts. While they are bemused why anyone could like hiking, they love camping, specifically the gadgetry of it: the portable stoves, the wire saws, the waterproof matches. This creates, as the saying goes, "a window of opportunity." A flint lighter might be a trade- off for 12 miles or so. While a really decent compass should be worth a couple of overnights. Bribery? Is your life completely free of little flyspecks of compromise?

Their sister, who rode in a pouch on my back during my second trek on the trail, is now 14 and another matter altogether. With that sophisticated assurance that comes with being a teen-ager, she invariably greets any proposal to go hiking with the studied pronouncement: "It's borrring!"

I recognize I have a certain debt to others when I use the trail; life is after all a seamless cloth. The Appalachian Trail Club is an organization of good-hearted people who handle all the lobbying vital to keeping the trail alive. The dues are pretty nominal and it's high on my list of things to do, sometime beyond the next set of braces and the class trip to Glassboro, New Jersey. I know that, in life, dues have to be paid.

Local chapters -- The Potomac Appalachian Trail Club serves the Washington area -- take care of trail maintenance. They like to think of themselves as selflessly giving up their weekends to clear trees that have fallen athwart the trail and repairing guide markers. One would think that a fair man would feel an obligation to them also. I have noticed, however, that all their energies in recent years have gone to make the ascents steeper; it's part of the mindless cruelty of the age we live in and I for one do not intend to be part of it.

One warning. There's something about hiking in the higher elevations of the East Coast that none of a score of guidebooks prepared me for. It turns your hair gray.