> It simply does not leave time for leisure or to unwind, but as I said previously if your work is what you would do with your leisure time then that's not an issue, as there is nothing to unwind from.

I don't qualify continuing to work as leisure time just because you happen to like your work. Work is work, regardless of whether or not you like it.

Also I don't believe that simply increasing the amount of hours you work on a startup will directly impact its success. Cutting the scope is almost always a better way to improve a startup's chances.