It's also pretty common in startup and executive culture to lie about how many hours you work. It's a machismo thing. In reality people rarely actually work 80+

It's also pretty common in startup and executive culture to lie about how many hours you work. It's a machismo thing. In reality people rarely actually work 80+ hours. Even if they are physically present that much they are not really working (in a productive / effective sense) for more then 50-60 hours of that time. Research has repeatedly shown that for most people productivity begins to decline after 40 hours a week and to tank after 50. Results can vary a bit from individual to individual and for different types of work. Knowledge work is usually worse in the sense that deep "flow state" focus can usually be sustained for even less time than this. Humans seem to be "burstable" in the sense that short duration crunch times can be done but they require rest afterwords to return to peak performance.