I think it's possible to work 60 hours per week productively. In order to do so, you need not only passion but a proper life setup. At least, it's important to have diversity not only in the work (more than one project) but in work environments. I would shrivel up and die if I had to spend 12 hours straight in an office building, especially in the winter when the days are short and 30-60 minutes/day of daylight outside time (yes, even when it's 25 F) is a mental-health necessity.<p>The issue with work hours is that most people work 55-60 hours per week including housework, commuting, in-office time, communication and lunches. That's a normal total (paid and unpaid) work week and it doesn't usually lead to burn out. (Yes, I count lunch as "work": there are usually social expectations that make it a lightweight form of networking.) The danger of pushing to 60 hours of "work time" is that the real work week becomes 75-85 hours, a level that's not sustainably productive for anyone. Personal errands go undone, housework falls behind, and these "time debts" pile up until they're unmanageable.<p>If you're going to work more than 40 hours per week, you have to outsource the housework. If you're doing your own cleaning and working six 10-hour days, you're destined for burnout. Car commutes, as well, are deadly. Sitting in traffic can incinerate 5-10 hours per week easily. The solution (if available) is either to get some of that work done on public transit, or replace the boring, stressful car commute with a bike commute, getting physical exercise on the way.<p>Also important is attention paid to the fact that burnout (and avoidance thereof) are not only functions of how much one works, but what one is doing outside of work. Physical exercise, keeping up friendships, leisure reading, travel, variety of cuisine, and some sort of spiritual focus (this needs not be tied to supernatural belief) are essential in order to keep perspective. <i>Not</i> doing these things, even at a 20-hour work week, is going to produce burnout over time.