Abstract Background Although the general assumption is that patients with rheumatoid arthritis (RA) have decreased levels of physical activity, no review has addressed whether this assumption is correct. Methods Our objective was to systematically review the literature for physical activity levels and aerobic capacity (VO_2max). in patients with (RA), compared to healthy controls and a reference population. Studies investigating physical activity, energy expenditure or aerobic capacity in patients with RA were included. Twelve studies met our inclusion criteria. Results In one study that used doubly labeled water, the gold standard measure, physical activity energy expenditure of patients with RA was significantly decreased. Five studies examined aerobic capacity. Contradictory evidence was found that patients with RA have lower VO_2max than controls, but when compared to normative values, patients scored below the 10^th percentile. In general, it appears that patients with RA spend more time in light and moderate activities and less in vigorous activities than controls. Conclusion Patients with RA appear to have significantly decreased energy expenditure, very low aerobic capacity compared to normative values and spend less time in vigorous activities than controls.