If you're one of the thousands of individuals who heads to the mountains to ski each year, you could end up with more than you bargained for if you're not in proper condition.

About 20,000 skiers will tear their anterior cruciate ligaments (ACL) this year, according to the American Academy of Orthopedic Surgeons. These, and other common skiing injuries, are preventable. All it takes is some pre-season conditioning and a proper warm up before hitting the slopes.

"There is no 100 percent guarantee against injury but there are steps people can take to significantly decrease the risk of injury while skiing," said Dr. Wayne Gersoff, an orthopedic surgeon at Columbia Rose Medical Center, Denver.

Common skiing and snowboarding injuries affect knees, wrists, thumbs, elbows, shoulders, hamstrings and ankles. These injuries can occur due to equipment problems (e.g. bindings that are too tight), people trying to ski themselves into shape, skiing without warming up and skiing when the person is tired.

"Now is the perfect time to get yourself into skiing shape," said Gersoff. "Preseason training will help prevent injuries as well as increase performance and make you stronger for a more enjoyable time on the slopes."

Gersoff recommends the following exercises to get in shape for the ski season:

Daily flexibility/stretching exercises.

Cardiovascular exercise, such as stairmaster, running, cycling, aerobics and swimming, for 20-30 minutes two or three day per week.

Abdominal work, such as sit ups, crunches and leg lifts, two or three days a week.

Lateral jumps (plyometrics) two days per week including side-to-side hops with cones or a small step, sliding machines or a jump rope.

Lunge walking one or two days per week.

Weight training, that includes up to four sets of 10 to 15 repetitions that work different muscle groups, three days a week.

Proper warm-ups to complement the workouts, such as a light jog or calisthenics before and after each workout.

A training program should at least include cardiovascular exercise with abdominal, stretching and flexibility exercises three days a week, said Gersoff.

Skiers should consult a trainer or physician with questions about techniques, starting a first-time fitness program and any heart or respiratory problems.

Address: Dr. Wayne Gersoff, Columbia Rose Medical Center, 456 East 9th Avenue, Denver, CO 80220.