Joggers who want to continue running in the winter's cold weather may do so without risking their health, as long as a few precautions are taken. So says Dr. George Sheehan, an experienced marathon runner from Rumson, N.J. and editor of Runners World magazine.

The 61-year-old cardiologist, a nationally recognized expert on running and health problems, has participated in 16 Boston Marathons but registered his best time, 3:01:04, in last month's Marine Corps Marathon in Washington. "That should lend a little encouragement to people who think they are over the hill," Sheehan said.

"There really aren't any dangers to running in the winter," he claimed. "Frozen lungs seem to be a figment of some writer's imagination. We're not sure that can occur. Studies have been done which show that air is already heated by the time it reaches the larynx."

But he sounded one cautionary warning about winter running. Exercise-induced asthma is directly related to the temperature and humidity of the air. Asthmatics, therefore, should wear cold-weather masks (available in drugstores) and ski masks which will help warm the air and keep the moisture in.

For most runners, Dr. Sheehan sees no problem in jogging in the winter's cold. "You can run at freezing (32 degrees) in clothes you can sit around in at room temperature. The body's metabolism takes care of most of your heat problems", he said.

Although the ground may become irregular from patches of snow and ice, and it can be difficult to get traction, the real problem facing joggers is adjusting to the cold air.

"It takes six to 10 minutes to warm up and during that time you can change your mind about the whole project," Dr. Sheehan pointed out. "Loosen up running in place in your home before setting out, and make sure to start off running against the wind.

"That way you'll tend to warm up and begin to sweat and when you return, the wind will be at your back. It's much warmer and you won't run the risk of getting overexposed."

Proper clothing is crucial to successfully battling the chill of winter's wind. Dr. Sheehan recommends wearing a ski mask, even at 40 degrees, and suggests putting on mittens rather than gloves, especially for those who have poor circulation in their hands.

"I usually wear a double layer of socks instead of gloves, and put on down mittens -- the type duck hunters and skiers use -- when it is very cold. I also use a cotton turtleneck because if you have three inches exposed between your chin and breastbone, you can really feel it.

"I tend to wear nylon T-shirts because they are wind- and water-repellant. The worst weather you can run in is when it is 36 degrees and raining. That chill gets down to your bones and can be awful."

Dr. Sheehan warns that joggers get easily chilled after long runs and that can lead to colds and flu. "It is incumbent on people to get warmed up as soon as possible after they run. If you already have a cold, it is better not to run. I'm likely to run with a cold in the summer, but in the winter you'll just drive yourself deeper into the ground."

Dr. Sheehan does not shower right after he runs. Instead he towels off and gets into something warm immediately. He suggests that you change running gear daily.