My husband, a great observer of the human condition and a teetotal abstainer from any form of exercise, said to me the other day, "If jogging is so much fun, why do all joggers look so miserable?"

Little does he know, since the joys of jogging are not revealed to the sedentary, that the pained look on joggers' faces masks a plethora of joys that James Fixx scarcely mentioned.

For instance, take jogging clothes. Lord, it's worth a third wind high to go jiggling along in a tightly modeled T-shirt, blazoned with a Kliban pussycat in sneakers, my hair sweeping out behind me dramatically in the wind, tanned legs with the superb muscle tone flashing from shorts slashed on the sides up to there. I know I am the cynosure of all eyes.

I know, too, to my supreme delight, that my neighbor, who flunked out of Weight Watchers, is sitting at her window in her curlers as I whirl by, eating her heart out (along with her second Danish).

Then there's the joy of male-jogger-watching. I check them all out, those handsome Adonii dashing along in their pelvishugging shorts, their second wind tucked under marvelous, wonderful-to-behold flat stomachs, the virile sweat pouring down. Well, it is an exhibition sport, isn't it?

Every jogger knows it's worth running ten miles just to brag about it. I have no shame about worming my jogging prowess into any conversation: Total strangers are likely to be regaled with a recital about my wind, speed and splendid cardio-vascular system. But my best brag comes during bad weather, when my sedentary friends say, "Surely you didn't go jogging in this weather?" And I offhandedly reply, "Of course, what's a little rain/snow/sleet/hail?"

It gives me untold joy, too, to find that all those years of studying English literature were not wasted; for here I am with a head full of poems to jog by, one for every mood and occasion.

TO COMPLEMENT A HANGOVER

In the fell clutch of circumstance,

I have not winced nor cried aloud;

Under the bludgeonings of chance

My head is bloody, but unbowed.

TO ESTABLISH A GOOD RHYTHM

(Never mind the sense of it)

Tiger! Tiger! burning bright

In the forest of the night,

What immortal hand or eye

Could frame thy fearful symmetry?

When a pulled tendon makes my stride irregular, I try something in iambic pentameter, accenting the second syllable in each line with my good foot:

Jog on, jog on, the footpath way,

And merrily hent the stile-a:

A merry heart goes all the day,

Your sad tires in a mile-a.

All joggers run on self-esteem. I often get mine bolstered from outside sources: from the diminutive third-grader on crossing guard duty who shouts "Wow!" as I pass him on my tenth lap. From my garbage man, who yells, "Right on, lady!" From nearsighted truck drivers. And from every dog in Montgomery County.

One joy of jogging I haven't even told my hairdresser about (and I tell him everything) is burping. There is nowhere in this civilized society where you can burp with impunity, except maybe in the bathroom with the shower on full. But out there jogging you can burp, I mean really burp - great, glorious, gross, resounding burps.

So here I am, uninhibited, the envy of all, loaded with muscle tone, rampany with self-esteem, but also a woman of a certain age whose ultimate joy comes every morning when I look down at my ancient legs and think, "Gawd, those old things can still run." And if I run fast enough no one will see my varicose veins. CAPTION: Picture, no caption, AP