Ankylosing spondylitis (AS) is an inflammatory disease of the spine. The disease mainly affects the spine-dominated medial structures, causing a series of functional and organic damage such as pain, stiffness and muscle fatigue, which in turn restricts the patient’s spinal movement and causes many inconveniences in the patient’s working life. Evidence-based medicine suggests that rehabilitation is the most important part of AS treatment. Although the efficacy of rehabilitation exercises and aerobic exercise has been mentioned in the literature, the details of what kind of exercises patients should take, how many times per week and how long each exercise should be are still unknown. In order to investigate the changes in motor function, spinal mobility, disease progression and quality of life in patients with AS after aerobic exercise, Dr. Jennings et al. from the University of São Paulo, Brazil, conducted a 12-week randomized controlled trial and published the results in the journal J Rheumatol, hoping that physicians and patients would have a more accurate and specific understanding of the effects of aerobic exercise and thus be more active in their treatment. A total of 70 patients with AS were enrolled in this trial. All patients were clearly diagnosed according to the Modified New York Criteria and had been receiving standardized medication, and none of the patients in this trial had any prior medical conditions that could affect the outcome of the trial, such as diabetes or cardiovascular disease. Seventy patients were unknowingly divided equally into a test group and a control group of 35 patients each. During the 12 weeks of the trial, patients in the test group performed three sets of 30-second stretches of the trunk and extremities three times per week, in addition to stretching exercises. In addition, each stretching session was preceded by 50 minutes of aerobic exercise, which consisted of a 5-minute warm-up – 40 minutes of walking (the patient’s anaerobic threshold heart rate was measured beforehand and the patient’s heart rate was always below the anaerobic threshold heart rate during the walking session) – and 5 minutes of rest. In contrast, patients in the control group performed only stretching exercises. Patients were evaluated before the start of the trial (T0), 6 weeks after the start of the trial (T6), at the end of the trial (T12), and 12B weeks after the end of the trial (T24) for a full assessment of spinal function (a combination of BASFI, HAQ-S, and 6-minute walk test results). A spinal mobility assessment (BASMI), disease activity assessment (BASDAI/ASDAS scores, CRP levels and sedimentation), and quality of life assessment (SF-36) were performed. After the test, the BASFI, HAQ-S, BASAMI and ASDAS scores were significantly improved in both the test and control groups, and the difference between the two groups was not significant. However, the 6-minute walking distance was significantly greater in the trial group than in the control group. At the same time, cardiopulmonary function was significantly better in the test group than in the control group. Based on these results, the researchers concluded that aerobic exercise, in addition to stretching, does not improve spinal function and mobility, nor does it delay progression of the disease, but it does increase walking distance and improve cardiopulmonary function in AS patients. Therefore, appropriate aerobic exercise in addition to regular rehabilitation would be beneficial for patients with AS.