Happily Extreme
“But even Friedman concedes that among the folks who live to work — the ones he calls “happy workaholics” — such strategies are irrelevant. And don’t try telling them that long hours and high stress will ultimately make them sick. “There are studies that look at the impact of weekly work hours on health, and two that link it to heart disease,” says Paul Spector, professor of industrial and organizational psychology at the University of South Florida. “But here’s the kicker: In order to pay the price, it has to be a job where you’re forced to work hours that you don’t want to.” In other words, if you like what you’re doing, there’s no physical risk. “The data suggest that people who are doing it because they want to are perfectly fine,” says Spector.”
By the way… nice (and effective) search on the Fast Company site.