Since as well aerobic as muscular deconditioning are apparent in persons with chronic low back pain and improvements in overall physical fitness can affect therapy outcomes in this population, ET specifically focussing on physical fitness can be advocated for NSCLBP rehabilitation. High Intensity Training (HIT), has been promoted as an effective and efficient training method for improving physical fitness and health related parameters in healthy persons. Also, HIT resulted in successful reconditioning and improvement of functional and disease related outcomes in persons with other chronic diseases such as multiple sclerosis, heart failure, COPD and cardiometabolic diseases. Although some studies showed promising results for the effect of HIT on low back pain such as high intensity isolated, evidence is still scarce and study results are unclear because of methodological shortcomings.To evaluate HIT for the rehabilitation of persons with NSCLBP, a therapy program was developed consisting of high intensity interval cardio and high load whole body strength training.