More and more, aerobics enthusiasts are giving up the fabled “burn” of strenuous exercise for more moderate workouts like tai-chi and yoga. The result: improved health without injuries and aches. Best of all, low-sweat exercises practiced regularly can help you lose weight and keep it off. If you want to get in shape but can’t keep up in aerobics classes, try some of these alternatives.

1. Tai-Chi
Calories burned per half-hour session: 125 to 150.*

This ancient Chinese movement, rooted in the martial arts, improves strength, flexibility, concentration, and balance by combining mental discipline with physical movement. When done correctly, Tai-chi can raise the heart rate to 60 percent of maximum, qualifying as moderate exercise. Thighs and hips do much of the work, just as in high-impact aerobics — but without the jumping.

2. Water Workouts
Calories burned per half-hour session: 180 to 200.*

Exercising in water is increasingly popular with people who have been injured by high-impact workouts. Participants can walk on underwater treadmills or perform arm, leg, and abdominal exercises. Minute for minute, it burns fewer calories than the same exercises performed on land, but many people find they can train longer, in part because water pressure helps blood circulate so that the heart doesn’t have to work as hard.

3. Yoga
Calories burned per half-hour session: 200.*

Now practiced by more than four million Americans, yoga has its roots in ancient Indian philosophy and improves flexibility, muscle strength, and endurance. It consists of deep-breathing exercises and “postures” or “poses” that are held for up to 20 minutes by advanced students. Yoga also involves muscle toning and some aerobic movement. The poses can be adapted to any fitness level. As you increase the depth of practice, the benefits increase. Some doctors advise learning yoga in a supervised class because certain positions can cause injury if done incorrectly.

4. Ballet
Calories burned per half-hour session: 150 to 180.*

You don’t have to be Baryshnikov to benefit from ballet: This graceful, smooth dance is becoming a popular way to stretch and strengthen underused muscles, and improve flexibility and coordination. An added benefit is improved posture: Many of the moves, like the first position (standing upright with the heels together and legs turned out at the hips, arms bowed in front of the body), force you to align your body and promote fitness discipline.

5. Neuromuscular Integrative Action (NIA)
Calories burned per half-hour session: 150 to 300.*

A blend of dance, ballet, tai-chi, yoga, and martial arts, its movements are fluid, circular, and linear. It’s done barefoot to music and resembles dance; a session leaves an exerciser sweaty, but not breathless. There are between 200 and 250 instructors nationwide; cost is about ten dollars per session. Call NIA Technique headquarters, 800-762-5762, for referrals.

*Calories expended depend on weight of the exerciser and intensity of the workout.

-By Diane Eicher