The purpose of the present study is to evaluate the effectiveness of a prehabilitation program on the recovery of patients undergoing a minimally invasive surgery for degenerative lumbar spinal stenosis. To do so, 40 participants will be recruited and randomized into two groups; intervention or control group. Participants in the intervention group will take part in a physical training program, three times a week for six weeks before undergoing surgery. The exercise program will be supervised and will aim at improving core muscles strength and endurance as well as spine stability. It is hypothesized that the prehabilitation program will significantly improve disability and pain intensity reported by patients after surgery. Ultimately, this study aims to improve health care of patients awaiting lumbar surgery but its results may also impact the management of patients awaiting spine surgery for various conditions.