A-Z of Skiing: U is for unweighting

The Collins English Dictionary does not recognise the word "unweighting". It permits a few imported skiing terms, such as aprÿs-ski ("social activity following a day's skiing"), mogul ("mound of hard snow on a ski slope, perhaps from South German dialect Mugl") and schuss ("straight high-speed downhill run"), but refuses an entry for one of the sport's key techniques.

The Collins English Dictionary does not recognise the word "unweighting". It permits a few imported skiing terms, such as aprÿs-ski ("social activity following a day's skiing"), mogul ("mound of hard snow on a ski slope, perhaps from South German dialect Mugl") and schuss ("straight high-speed downhill run"), but refuses an entry for one of the sport's key techniques.

A determined student could only conclude - by construing unweighting as the opposite of "weighting" - that it describes the dubious statistical process of making a survey sample unrepresentative, or the salary reduction suffered by an employee who leaves London. So what actually is unweighting?

It is a sudden movement that, once completed, effectively lessens the weight with which the body presses down onto the ground. The same effect can be achieved by two apparently contradictory movements: upwards into a stretch, or downwards into a crouch. In both cases, the pressure which a skier exerts on his or her skis will be reduced.

Since body weight is the only means that skiers - and, more obviously, snowboarders - have to control their edges, unweighting might seem a foolhardy manoeuvre. Yet ski instructors insist on it: that's what the process of initiating a turn ("plant the pole, straighten the knees") is all about. Unweighted skis turn more easily towards the fall line, both because of the reduced grip and because they lie flatter on the snow.

As the knees pass across the centre-line of the skis, re-weighting will force the uphill edges into the snow, and complete the turn.

That is "upward" unweighting; the opposite - going into a crouch - is most commonly used to cope with bumpy terrain. Skilled skiers will increase upward unweighting by using the flex of their skis to help jump them from turn to turn.

If you doubt the physics of upward unweighting, try this simple exercise: jump into the air. When you have left the ground, consider how much pressure you are exerting through your feet. It's definitely the quickest way of losing weight.