Ninety-six patients who had undergone first-time discectomy for herniated lumbar intervertebral discs were consecutively randomized to two physical rehabilitation programs: a program of high-intensity, dynamic back extension and abdominal exercises with occurrence of low back pain being the limiting factor or a traditional program of mild, generally mobility-improving exercises within pain limits. Both groups underwent 14 hours of treatment during a 6-week period 5 weeks after surgery. At 26 weeks' follow-up, results indicated that patients who did the high-intensity exercises experienced greater success with regard to the patient disability-index and work capabilities. After 1 year, a trend that favored the use of intensive exercises could be observed. No differences were found in pain or objective measurements. A rehabilitation program of intensive exercises with occurrence of back pain being the limiting factor appears to increase patient behavioral support, resulting in work capacity improvements and patient self-rated disability levels. The results indicate that a 6-wk, 14-hr postoperative rehabilitation program is inadequate if objective postoperative deficit improvements are the desired goal.