As am I. Working 60 hours/week is hard and a huge strain on the body. Doing 80 hours/week for months/years at a time? Work 8-8 7 days/week? Never seen it unless a release is imminent.
From February of 1996 to late 2000, I averaged about 65-80 hours per week, between a full-time office job and a second job delivering pizzas. A few times, I actually hit 90 hours.
At my peak, my schedule went something like this...
Regular M-F office job from 7:30-4, sometimes 8-4:30. PLUS...
Monday: 5-midnight
Tuesday: 5-midnight
Wednesday: off
Thursday: 5-midnight
Friday: 5pm-1am
Saturday: 5pm-1am.
And those ending times were approximate...often we got out of there later, depending on how long it took to clean up the store at night.
I used to come home from my regular job Wednesday night, crash on the couch, and fall asleep immediately. Saturday, I often slept the whole day, until it was time to go into work. And then, I was usually wired up Saturday night, so I'd hang out with friends or co-workers at IHOP or a local diner or some other goofing around. And on Sunday, if I woke up before noon, it was rare.
Once I got all the debt from my divorce paid off, I started saving up, and slowly started cutting back my hours. For the final year or so, I was down to mainly 5-close Thurs/Fri/Sat.
That was also from the age of 26 to 30. I'm about to turn 42 soon, and have gotten a bit complacent and out of shape. I dunno if I could ever go back to a schedule like that. Maybe, I could acclimate to it eventually, if I really had to? One good thing about it was that having two separate jobs broke up the monotony a bit. Having to pull 65-80 hours per week at the same job would probably drive me insane really quickly!