T'ai Chi is a specific training program aimed at teaching people how to maintain balance so that they can withstand the attack of an enemy and remain on their feet. It involves slow, purposeful movements that apply the same forces on muscles that require far heavier forces with faster movements. So T'ai Chi strengthens muscles with far less likelihood of injury.
Older people often lose coordination and are at increased risk for falling. With T'ai Chi, an older person can get the same strengthening of muscles and balance control with slow movements that a younger person gets by using far faster movements with much greater force on muscles. It can help older people improve balance, which can protect them from falling and breaking their bones. It is also a safe way to build muscle strength. The risk of injury in T'ai Chi is very low, which is an advantage at any age but exceptionally important for older people who are starting a new exercise program. See report #1550 for more tips on starting a new exercise program.