How can you help your child become physically fit? Health experts suggest you:

*Limit your children's TV viewing time. Greater admiration for the tube than for the human body is the factor experts cited most often as a deterrent to exercise.

*Encourage youngsters to walk or ride bicycles rather than depend on motorized transportation. Of course, the best way to encourage this is through example.

*Establish a family workout routine. Set aside 20 minutes daily for doing a variety of exercises. Chart areas of improvement -- kids love to see their progress.

*Promote "lifetime" sports such as running, bicycling, swimming and racquet sports in addition to traditional team sports.

*Check on the physical education program in your child's school. Encourage schools to provide materials such as Fitting In and Fitnessgram and to regularly administer the Presidential Fitness Test.

*Control your child's diet. Teach your child about the dangers of overindulging in junk food -- and don't overindulge yourself. Resources

*The American Alliance for Health, Physical Education, Recreation and Dance, provides brochures on children's fitness and samples of Fitting In magazine and the Fitnessgram. 1900 Association Dr., Reston, Va. 22091.

*The President's Council on Physical Fitness and Sports offers a free book for parents who are interested in evaluating the fitness program at their child's school called "Physical Education: A Performance Checklist." They also have brochures on "The Physically Underdeveloped Child" and a basic youth fitness program called "Get Fit." Write them at Department 29, Washington, D.C. 20001.