Low back pain is a common but severe health problem. Chronic low back painaccounts as a heterogeneous entity seeking to match specific interventions to subpopulations. The present study seek to describe the prevalence of gluteus medius weakness in people with chronic low back pain and test the effectiveness of a gluteusmedius strengthening exercise intervention in people with chronic low back pain. Although gluteus medius weakness is common in people with low back pain and treating this weakness with a targeted exercise intervention is effective, it is not better than a standard stabilization exercise intervention. Doing exercise is likely more important than what exercise is done.