Study leader Leigh F. Callahan of the University of North Carolina at Chapel Hill, N.C., said the study involved 346 patients with an average age of 70 who had self-reported arthritis.

The participants were divided into an intervention group that took part in the Arthritis Foundation Exercise Program -- exercise classes at basic and advanced levels that met for one hour twice a week for eight weeks -- and a control group that was offered the program after eight weeks.

The intervention group completed self-report assessments at three months and six months after completing the program.

The study, published in Arthritis Care & Research, showed that the intervention group had significant improvements in pain, fatigue and managing arthritis at eight weeks, and maintained improvements in pain and fatigue at six months.