I guess it depends on the kind of job but at least with focus heavy tasks like programming I can already notice my error rate increase significantly by hour 7 or so. I can’t imagine working 10 hours a day without spending half of the next day fixing stupid mistakes from being overly tired.
I find that I’m pretty much useless after 4 hours. I usually do a 4 hour stretch during the day and then hop back on for another 2 hours when the kids are down and that seems to be the most productive for me.
I guess it depends on the kind of job but at least with focus heavy tasks like programming I can already notice my error rate increase significantly by hour 7 or so. I can’t imagine working 10 hours a day without spending half of the next day fixing stupid mistakes from being overly tired.
I find that I’m pretty much useless after 4 hours. I usually do a 4 hour stretch during the day and then hop back on for another 2 hours when the kids are down and that seems to be the most productive for me.