Wow, I'd be getting 8 hours sleep a night! Seriously, I'm baffled by people who voluntarily subject themselves to these long working hours. If you can't get the job done in 40 hours a week, the the work load needs to be cut. The more that workers continue to work longer than this then the more corporations will start expecting this abnormality from everyone. Being "on call" should be a rarity; if the entire staff is on call every day, then something is broken. If the same worker is on call all the time then something is broken. If the company treats "on call" as free overtime then something is broken. For god's sake, if you think this is normal then STOP and get a new career. It is not healthy to work those long hours, it is not healthy to go home and continue the office work from there, it is not healthy to be a slave.
At the very least, the first thing to do when getting free time is nothing. Sit down and do literally nothing. Stop panicking every minute about what the corporate overlord will think if people start doing nothing.
The US is considered a joke by the rest of the world, the US worker is being viewed as a workaholic who never takes a vacation before retirement.