When snow, ice and frigid weather blast into town, watch out, says the American Chiropractic Association (ACA). Winter recreational activities and chores can pose problems for the outdoor enthusiast whose body is not in condition. Winter sports like skating, skiing and sledding can cause painful muscle spasms, strains or tears if you're not in shape. Even shoveling snow the wrong way, clambering awkwardly over snow banks, slipping on sidewalks and wearing the wrong kinds of clothing can all pose the potential for spasms, strains and sprains.

Simply walking outside in the freezing weather without layers of warm clothing can intensify older joint problems and cause a great deal of pain. As muscles and blood vessels contract to conserve the body's heat, the blood supply to extremities is reduced. This lowers the functional capacity of many muscles, particularly among the physically unfit. Preparation for an outdoor winter activity, including conditioning the areas of the body that are most vulnerable, can help avoid injury and costly health care bills.

"Simply put, warming up is essential," says Olympic speedskating gold and silver medallist Derek Parra. "In fact, when pressed for time, it's better to shorten the length of your workout and keep a good warm-up than to skip the warm-up and dive right into the workout. Skipping your warm-up is the best way to get hurt." Parra, who took both the gold and silver medals during the 2002 Winter Olympics in Salt Lake City, Utah, adds that, "You can complete a good warm-up in 15-20 minutes. And believe me, it will make your workout more pleasant and safe."

Derek Parra and the ACA suggest that you start with some light aerobic activity (jogging, biking, fast walking) for about 7-10 minutes. Then follow these tips to help you fight back the winter weather:

• Skiing - do 10 to 15 squats. Stand with your legs shoulder width apart, knees aligned over your feet. Slowly lower your buttocks as you bend your knees over your feet. Stand up straight again.
• Skating - do several lunges. Take a moderately advanced step with one foot. Let your back knee come down to the floor while keeping your shoulders in position over your hips. Repeat the process with your other foot.
• Sledding/tobogganing - do knee-to-chest stretches to fight compression injuries caused by repetitive bouncing over the snow. Either sitting or lying on your back, pull your knees to your chest and hold for up to 30 seconds.
• Don't forget cool-down stretching for all of these sports - At the bottom of the sledding hill, for instance, before trudging back up, do some more knees-to-chest stretches, or repetitive squatting movements to restore flexibility.

Shoveling snow can also wreak havoc on the musculoskeletal system. The ACA suggests the following tips for exercise of the snow shoveling variety:

• If you must shovel snow, be careful. Listen to weather forecasts so you can rise early and have time to shovel before work.
• Layer clothing to keep your muscles warm and flexible.
• Shoveling can strain "de-conditioned" muscles between your shoulders, in your upper back, lower back, buttocks and legs. So, do some warm-up stretching before you grab that shovel.
• When you do shovel, push the snow straight ahead. Don't try to throw it. Walk it to the snow bank. Avoid sudden twisting and turning motions.
• Bend your knees to lift when shoveling. Let the muscles of your legs and arms do the work, not your back.
• Take frequent rest breaks to take the strain off your muscles. A fatigued body asks for injury.
• Stop if you feel chest pain, or get really tired or have shortness of breath. You may need immediate professional help.

After any of these activities, if you are sore, apply an ice bag to the affected area for 20 minutes, then take it off for a couple of hours. Repeat a couple of times each day over the next day or two.