Contact your physician first before starting an exercise program.
Always wear appropriate safety gear. If you bike, for instance, use a bike helmet.
Wear appropriate shoes for each sport.
Warm up before exercise.
Exercise for at least 30 minutes a day.
Exercise with a buddy.
Never increase your activity (distance walked or weight lifted) by more than 10 percent a week.
Avoid the same routine two days in a row to work different muscles. Walk, swim, play tennis or lift weights. Different activities work different muscles.
Stop exercising if you experience severe pain or swelling, and contact your physician.