For years, people with osteoarthritis have been advised by their doctors to exercise at least 20 minutes a day, and for years, most of them claimed that they did. Then researchers at Northwestern's Feinberg School of Medicine decided to stop asking about exercise and instead outfit 1,000 patients with an accelerometer that would track their actual movement. Guess what? "The physical activity rates were much, much lower than reported," was the way the lead author put it in a Northwestern news release. The bad news is, lying to the researchers is the least of their problems. Lying on the couch is a greater concern. The researchers found that that fewer than one in seven men and one in 12 women met the federal guidelines 150 minutes per week of moderate-intensity, low-impact activity for arthritis sufferers. Put another way, more than half of women and 40 percent of men with arthritis are couch potatoes.