Different types of exercise help a person correct specific problems. For example, exercises that stretch the spinal column and strengthen back muscles will improve posture. Other exercises help with problems of balance. Coordination and dexterity of movement can also be improved through suitable exercises. Muscles must be used to remain strong.
Breathing exercises help prevent infection, and also have a relaxing yet energizing effect.
There are centres that offer specialized exercise programs, and you are encouraged to participate in these. However, for maximum benefits, regular exercise is indispensable. It is daily practice that builds strength. All these don't require any special equipment or a professional trainer. Nothing can be more important than to conserve your ability to move easily.