For a complete workout, think cross-country

Wherever there's a half-decent covering of snow around, runners and joggers can have an even more satisfying workout during the winter months than their normal thump-thumping along the pavement.

Cross-country skiing has been called the second-best aerobic exercise for overall fitness. Swimming usually gets the nod for best-all-around. But cross-country skiing not only exercises everything that running does, it also makes greater demands on the upper body. Using those poles to help propel yourself forward contributes to overall physical fitness, and burns off a few extra calories as well.

Some say that a cross-country skier can burn up as much as 1,000 calories an hour on a cold winter day. (A pound equals 3,600 calories.) The high caloric burn in Nordic skiing comes not only from the exercise, but also from the body's need to generate heat to stay warm.

And lest you think that skiing is a cold sport, go out for a brisk cross-country ski for 10 minutes or so and you'll be amazed at how fast you want to peel off excessive clothing. That's one reason skiers dress in layers. You can get very warm very fast.

But whether you put on a pair of ''skinny skis'' for a workout or merely to enjoy the winter countryside, you can practice the sport at your own pace. That's one of its beauties - and one reason an estimated 4 million newcomers have tried it in the past 10 years.