BACKGROUND AND PURPOSE: The purpose of this study was to compare exercise during dry-land bicycle ergometry and running in water with a flotation device in individuals with rheumatoid arthritis. SUBJECTS: Eight individuals with adult-onset rheumatoid arthritis, between the ages of 30 and 40 years (X = 35.88, SD = 2.85), participated. METHODS: Each subject did a graded maximal exercise test on a stationary bicycle and in the water wearing a flotation device, while oxygen uptake (VO2), heart rate (HR), pain, rating of perceived exertion (RPE), minute ventilation (VE), respiration rate, tidal volume (VT), and respiratory exchange ratio (R) were monitored. RESULTS: Higher maximum RPE and R were seen during water running, whereas higher VE and VT were seen during bicycle riding. Heart rate, R, and plateauing VO2 data indicated that a true physiological peak VO2 was reached during the bicycle test. Peak VO2 and HR were similar for either water or bicycle exercise. These findings show that with both forms of exercise, subjects were able to reach training levels as set by the American College of Sports Medicine. CONCLUSION AND DISCUSSION: The water exercise, therefore, provides a means of exercising for individuals with rheumatoid arthritis. It allows them to reach the needed training levels in a comfortable aquatic environment.