[matwood]

Founders are already 'working' more than that. They are typically thinking about their company with every waking hour.

With that said, it doesn't mean they are not getting plenty of sleep. What it means is that when they are not sleeping, they are probably working. At the gym, they are probably thinking about work. At social events, they are probably thinking about work. Etc... It's just the nature of getting a company off the ground.