The surgical procedure for lumbar surgery can last from one to eight hours depending on what needs to be done. For example, spine fusion usually takes much longer than discectomy. Many people report immediate improvements in the way they feel after awakening from the surgery. However, strengthening your weakened muscles and soft tissue surrounding and supporting your trunk will require a long-term program of exercise and physical therapy. Although many people see and feel immediate improvements, they often get added benefits with a comprehensive rehabilitation program.