When it comes to fitness, motivation is hard to come by. Here are a few ideas to kick-start your exercise plan.

It is all but inevitable: Come springtime, you are out of shape. And who can blame you? Despite health-club memberships and home treadmills, the motivation to exercise seems to fade as the temperature drops. The hectic holiday schedule may be to blame, or perhaps sweating indoors doesn't appeal to you. Whatever the cause, inactivity harms the body, and it makes getting active again all the more difficult.

According to fitness expert Susan Smith Jones, Ph.D., almost anyone can get in a rut--it's simply easier to be out of shape than it is to exercise. To get over the hump, Jones suggests a few easy ways to find and keep your motivation:

• Commit to 21 straight days of exercise. It takes some three weeks to overcome the resistance to working out. If you can keep it up that long, your new exercise routine loses its novelty and becomes part of your life.
• Post your exercise goals where you can see them and keep track of your progress. It's a lot harder to "forget" about exercising if your goals are taped to your mirror or stuck on your refrigerator door. Monitoring your fitness success will help provide positive feedback.
• Exercise with a friend. Make it a social commitment as well as one to fitness.

One way to make exercise interesting is to take on a new approach to working out. In recent years, many people have turned to yoga as an alternative form of physical activity. Yoga's high popularity seems to derive from its low-impact style and its equal emphasis on the mind and the body.

There are several forms of yoga, but Hatha yoga is the kind most often practiced in the West. Hatha yoga concentrates on three aspects: controlled breathing, postures and meditation. The slow, deep breathing patterns of Hatha yoga are intended to promote relaxation, while the postures work on strength and flexibility.

The health claims of yoga extend from reducing stress and slowing the base respiratory rate to lowering blood pressure and fighting heart disease. Although the full power of yoga has yet to be proven in medical trials, some studies have hinted at the truth behind the claims. The practice of yoga seems to have pain-relieving benefits, for example. A recent study reported in the Journal of the American Medical Association indicated that daily yoga can reduce the pain associated with carpal tunnel syndrome.