"Keep it moving.. we're still walking forward.."
Massoud Mofid has been taking this water workout class for 15 years to help his osteoarthritis.
"The pain was mainly down in the knees. I was able to walk perhaps at first, two to three blocks then it shrank to almost one block."
Now new research from the University of Minnesota School of Public Health shows that certain types of exercise may help knee osteoarthritis more than others.
"If you do strengthening exercises, if you do low impact aerobic exercise, if you do some aquatic exercise you can improve your life, and you can improve your quality of life and reduce your pain," says Dr. Kurt Spindler of Vanderbilt Sports Medicine Center.
The Arthritis Foundation sponsors programs like this one all across the country for thousands of people coping with arthritis.
Osteoarthritis is a joint disease that is the number one cause of disability in the U.S. Doctors say sticking to an exercise program is key to relieving pain and improving mobility.
"If you moved the knee and get the knee moving gently, under low loads, it is very healthy for your tissues around the knees both your arthritis as well as your tendons and ligaments," says Dr. Spindler.
Longtime osteoarthritis sufferer Kit McCormick agrees working out in the pool helps her stay active.
"I'm doing things in the water that I cannot do on land, but when I get out of the water, it's wonderful."
Proving the right, consistent exercise program can make all the difference.
According to the CDC, approximately 1 in 2 people may develop knee osteoarthritis in their lifetime.