Exercise and changes in health status in patients with ankylosing spondylitis.

BACKGROUND Although exercise is a commonly recommended treatment for ankylosing spondylitis (AS), little is known about the effectiveness of unsupervised recreational and back exercises. We examined the effects of recreational exercise and back exercises on patient-reported pain severity, stiffness severity, and functional disability in a prospective longitudinal study of 220 patients with AS. METHODS Participants provided information on exercise habits and health status every 6 months using mailed questionnaires (median follow-up, 4.5 years). Pain severity and stiffness severity were measured using visual analog scales, and functional disability was measured using the Health Assessment Questionnaire (HAQ) Disability Index. RESULTS Among all patients, there were no associations between either the number of exercise minutes per week or the number of days of back exercise per week and short-term (6-month) changes in pain, stiffness, or HAQ Disability Index. However, among those who had AS for 15 years or less, pain scores were 0.18 points lower (on a scale of 0-3; P =.04), and stiffness scores were 6.4 points lower (on a scale of 0-100; P =.005) during periods with more than 200 minutes per week of exercise compared with periods with 0 to 30 minutes of exercise per week. Among those who had AS for more than 15 years, pain scores were 0.11 points lower (on a scale of 0-3; P =. 03), and HAQ Disability Indexes were 0.08 points lower (on a scale of 0-3; P<.001) during periods with 5 to 7 days per week of back exercise compared with periods when back exercises were not performed. Less intense levels of exercise were not associated with improvements in health status. CONCLUSIONS Unsupervised recreational exercise improves pain and stiffness, and back exercise improves pain and function in patients with AS, but these effects differ with the duration of AS. Health status is improved when patients perform recreational exercise at least 30 minutes per day and back exercises at least 5 days per week. Arch Intern Med. 2000;160:2969-2975