When you live where you work, what do you do with your downtime? Especially when you can't leave?
I wouldn't expect anyone to put every hour of every day working, they use their off-time to make videos, watch movies, talk to family, play guitar, etc. At any given moment there can be up to 150 experiments happening on the ISS. Sure, they make videos and he talks to classrooms on Earth but most of those videos are at most 20 minutes, what do you think they do during the 8-12 hours actually working? They recently fixed an ammonia pump used to cool their systems and keep the station running with the first unscheduled space walk they've ever done.
http://en.wikipedia.org/wiki/Scientific_…