Teddy Roosevelt, the 26th U.S. president, once said "the best prize that life has to offer is the chance to work hard at work worth doing."
Recent research suggests he may have been more right than he knew: Life's "best prize" might actually extend life itself.
Our common perception is that retirement is a time when we can relax and take better care of ourselves after stressful careers. But what if work itself is beneficial to our health, as several studies suggest?