Let's say I work at my most productive hours and I do a lot of work. At a certain point, I will become tired. Self-discipline might make me work for another hour or so but after that the quality of the work will start to suffer.
I could do small stuff that doesn't require my full attention. Like doing little household chores.
Eventually, there comes a time when I have to relax. I don't want to watch the some crappy television program, because that doesn't bring me any further to my goals.
Which relaxation options can I use to re-energize myself, that are still usefull and don't make me any more tired?