I consider my self a fairly hard working person, in my first job I've seen situations where people came in on a Monday and would go to their homes next Monday. I've done a full time start up with a day job, quite literally coding every waking hour of my life(like 2 - 4 hours sleep a day) for years. And then I relocated from Bangalore to Bay Area for a while, and met a few of our Chinese colleagues- Even by my standards the Chinese were in a different productivity league altogether.
One person I knew would have three monitors, would eat at desk all the three meals, not sure when he even took breaks, but he kind of worked all the time, I mean literally. Would watch tickets in one screen, production issues in one, and work in another one. He'd read every ticket, feature request, pull request, and comment every where, knew everything and would just outperform anybody by some factors(Mind you people in our team I knew were kind of legends themselves). It ain't just the hours, they through and through dominated the initiative. You stood no chance.
I knew several Chinese colleagues and friends like these. They are all good people wanting to make a good life by working hard, nothing to blame them. But it was kind of an unwritten rule that if you had two Chinese working in your team, you had no chance beating them.
Im in serious awe of the Chinese culture. They also seemed to have very little gender discrimination, and in general little less hyper about things like religion etc. I guess all this things give them a natural edge.
So yeah, not all long shifts are equal.