If you're planning a ski holiday this winter or just want to tone up after Christmas and the New Year, beware that you may be heading for more than just aches and pains at the gym or on the slopes.

Every year, winter holidaymakers sustain pulled muscles, ripped tendons and twisted knees when they launch themselves into a strenuous exercise regime on the piste after being in couch potato mode for so long.

Those who go skiing after being sedentary all year run the risk of serious leg injuries, says sports injury therapist Sarah Humphreys, of the Sports and Physical Education Network at Leeds Metropolitan University, while gym newcomers should take care not to overdo it initially on the machinery.

People simply try to do too much too soon, says Humphreys.

"It's caused by over-exertion. When people aren't fit, joints, tendons, ligaments and muscles aren't as pliable and you can't use them to their fullest extent."

Warming up should be through cardiovascular exercise such as a power walk, she adds, while stretching exercises should be done at the end of a gym session to warm down.

SKIING HAZARDS

For every 1,000 people skiing in a day, between two and four will need medical attention, says Dr Mike Langran, a ski patrol doctor at CairnGorm Mountain in the Scottish Highlands.

Langran, who also runs the website ski-injury.com, says knee injuries are the most common for skiers.

Knee ligaments - the medial collateral ligament (MCL), anterior cruciate ligament (ACL) and lateral meniscus - take up most of a doctor's workload, accounting for 30-40% of all alpine ski injuries.

A mild sprain of the MCL could see you back on the piste in a couple of days, while a ruptured ACL means it's time to change your flights and head for home.

Shoulder and thumb sprains are also common.

AVOIDING SKI INJURIES

In an ideal world, you should train for at least two months before your ski holiday.

But even a 15-minute stretch before you set off each day can save a lot of agony later on, Langran advises.

Training before the holiday should focus on building muscular endurance to help avoid fatigue during the day's skiing.

You should also do exercises promoting co-ordination of joint movements and balance. Many clubs and leisure centres run classes specifically design to prepare you for skiing.

Strengthen muscles at the front of the shins by sitting in a chair, placing your feet flat on the floor and and lifting your toes as far as you can, keeping your heels on the ground.

Repeat until you feel your shin muscles getting tired and do that a couple of times a week.

Warm up and down properly - spend a few minutes gently stretching your hamstrings, thigh muscles, hips and calves before and after going on the slopes.

Hold each stretch gently for 30 seconds. It shouldn't hurt.

GYM HAZARDS

Shin injury is the most frequent problem - a result of doing too much on the treadmill or too many high-impact classes before the body has had time to wake from its muscle slumber.

But one of the most common causes of injury is people misusing the equipment, says Humphreys.

Men in particular pile too many weights on the machines and then don't use them properly, which can put pressure on the wrong muscles, she says.

Using apparatus incorrectly can cause muscular imbalance and referred pain.

For example, the correct way to use the 'pec deck' - the machine where you squeeze two vertical bars together with your arms - is to keep your back straight and shoulders back and squeeze those muscles.

But some people throw their whole body into the exercise to move the weights and end up using the wrong muscles, Humphreys says.

Problems with the lumbar spine can occur when a poor technique is repeated over and over again.

Weight machines should not be used in a jerky fashion, but they often are.

"People concentrate too much on weight and not technique," she adds.

Joints should not be fully extended on the machinery as they can lock. Newcomers should stop a centimetre short, hold the position for a few seconds and relax slowly.

Some people even use the running machine wrongly. If they are tired, their head will drop which puts a tremendous load on the spine.

AVOIDING INJURY

Don't do too much too soon. Start off with what you feel comfortable with and gradually build up resistance.

Walk up stairs rather than taking a lift, take a brisk walk rather than catching a bus and do some exercises at home, such as squats (keeping your feet flat on the floor with a straight back), lunges or calf raises (stand up straight and lift on to the balls of your feet and down again).

"People need to differentiate between bad pain and good pain," says Humphreys. "If you have done a very hard session and ache for 48 hours afterwards, you've done too much. You should just feel like you've worked the muscles and woken them up."

Unfortunately there is no quick fix for couch potatoes.

"Initially stick to at least five 20-minute exercise sessions a week," she says. "If you are going skiing look at preparing to get fit at least four to six weeks beforehand.

You can't cram. That's where the danger lies. Your body adapts very slowly."

Don't increase the distance or duration of your workouts or the weights by more than 10% each week and try to avoid working out in the gym on consecutive days if you are a newcomer, as your muscles need to recover.

By Hannah Stephenson