Your doctor will tell you when to begin each type of exercise. In addition to your exercise program, your doctor may suggest learning about the importance of posture and proper technique for sitting, lifting, and other activities. You may also need the help of a physical therapist or other professional, and may need medication for some period of time. But none of these can take the place of exercise. These allow you to work out without subjecting your back to the repeated impact produced by jogging or aerobic dance.
Any activity is better than none.
Within 3 months you should be able to achieve the full schedule. Avoid racing bikes. If you walk, stand comfortably straight without slouching. Preserve a slight arch in your lower back, and keep your stomach muscles slightly tensed. First, it strengthens and stabilizes the muscles of the back and abdomen so they can support your back and protect it from strain.