They work.

They, meaning screws in your shoes, will keep you out there walking and running all winter long. No excuses anymore about it being too slippery; forget your fear of falling on the ice. These screws were made for walking, or running.

With perfect laboratory conditions in my area of Wisconsin last week -- an "official" blizzard dumping more than a foot of snow, followed by a couple days of melting -- I decided the time had come to try the studded running-shoe idea. Studs work on tires (although illegal in lots of places), so why not on feet?

My hardware man, with his best the-customer-is-always-right smile, counted out 16 of his three-eighths-inch hex-head screws. No, I'd never heard of hex-head screws before either. They have six sides; now you figure out how they got their name.

At four cents each, the equipment for this little experiment would not, I figured, break the bank. But if they ruined my $49.95 running shoes, it'd be a different story.

But look at that sun-glistening snow, blue sky and the cardinals flashing overhead. Feel how fresh the air, and look at that road, just waiting for your footprints. I had to get out there, and I didn't want to worry about breaking my tailbone as a runner friend of mine did, after slipping on a patch of ice buried beneath fresh-fallen snow.

And that's why my 64 cents worth of hex screws in my little brown paper sack felt more precious than rubies. For when could rubies give you a flight through a frosty morn, feet sure on snow and ice?

At least that was my fantasy, as I labored over my shoes on the kitchen table. It took me, however, much too long -- about a half-hour per shoe -- to work in the screws, and the trial run turned out to be on a frosty eve rather than a frosty morn. But that maiden voyage far surpassed any fantasies. My plan was to walk a mile to the post office and I wound up running five, transported on winged and cleated chariots through snowy lamp-lighted streets.

What was once an apprehensive, body-tensing experience -- when am I going to slip and fall? -- had become a liberated flight of winter.

The idea, proffered in this month's Runners World magazine, works, and of course I had to call the man in Anchorage who presented it.

"I know; it's terrific. It's addicting," agreed exercise physiologist, Alaska Pacific University wellness instructor and lifestyle counselor John Schlife.

"Even though my friends used screws in their shoes, I held out for the longest time. Now running with them has become an addiction, maybe because my whole body feels so much more relaxed."

Schlife (rhymes with life) has done 80 marathons, and runs daily for a total of about 100 miles a week, despite ice, snow and typical 20-degree temperatures. He's run at 24 below in Anchorage and 55 below in Fairbanks.

"You get used to the cold," he shrugs. Schlife, 44, who has a PhD in exercise physiology, moved to Anchorage a few years ago when he was invited to launch a wellness program patterned after one he started in Salina, Kan., believed to be the first in private family medicine.

"There's a lot more to being well than just not being sick," he said. Wellness he defines as "living at a level where you have energy to do more than just work, but to do all kinds of things that are part of living life to the fullest. You're not just surviving, you're thriving."

Some kind of regular exercise -- something to get people moving -- is, of course, part of his prescription for virtually everyone.

Back to studded running shoes. Schlife has used them for three years, and now views his concerns about adverse biomechanical effects as unwarranted. "I've had no knee, ankle or foot pain from the studs," he said.

Schlife is careful, however, to avoid placing the screws in the toe area of the shoes. Instead, four screws are inserted on each side of the shoe, two or three inches apart, starting in the heel area and winding up a couple inches short of the toe section.

His technique for installing the screws, as pictured in Runners World: Grasp the head of the three-eighths-inch hex-head screw with pliers. After several vigorous turns, the screw is caught in the outsole of the shoe, and with a few more turns is in place.

When the screw heads wear down, Schlife replaces them, and when spring comes, simply removes them and resumes summer running in the same shoes. The screws do not seem to deflate any air cushioning.

With some top orthopedic physicians prescribing running -- not walking -- shoes for walkers, the studs seem like a good idea for everyone. That is, everyone who refuses to let a little snow and ice get in the way of a good walk or run.

Any comments are welcome, but I predict that some profit-minded manufacturer is going to zero in on the idea, and it won't be long before you see "winter running shoes" -- studs already installed for a price -- on your shoe-store shelf.

And what else does Alaskan Schlife wear for winter running?

At even 24 below, he wears only a vented Gore-Tex running suit with polypropylene lining, over undershorts and a long-sleeved T-shirt. Also, a ski cap with Gore-Tex lining, wool socks and Gore-Tex mittens.

Some other basic reminders for winter exercising:

Remember that sweat is your biggest enemy in the cold. Wear garments next to your skin that wick the moisture away from the body, such as polypropylene or other synthetics.

Don't forget that cotton, however wondrous a fabric, is a terrible choice for wearing next to your skin in the cold. It will absorb -- not wick -- your sweat, and you'll soon be wrapped in your own ice. This includes your feet.

Try wearing your long Lycra tights (if you have them) -- instead of long underwear -- under your wind pants. They wick sweat, are lightweight, insulating and besides, give extra support.

And another idea from Running and FitNews, the newsletter of the Bethesda-based American Running and Fitness Association: On bitterly cold days, try wearing plastic bags over your synthetic or wool socks to keep the chill out and the heat in.