I've been finding that I could really use about 15 minutes of downtime in the early afternoon. When tele-commuting, I found that if I took 15 minutes to do nothing in the middle of the day, I would finish and be fine and fresh for the rest of the day. If I don't take that rest, I am fatigued for the next several hours.
Unfortunately, my work environment (as most peoples) doesn't allow me to find a place to lay down for 15 minutes without some serious stigma being attached to it.
So, I'd be much more efficient if I could take a short break but I can't. Oh, well. It means that my work is substandard some afternoons.
P.S. In terms of doing nothing, I'm talking about the mundane kind rather than the meditative type.
I find that sometimes I need to rest and just have no inputs for about 15-20 minutes. I wonder if this has to do with ADD or if it is just me. One of the reasons that I think it might be ADD related is that I know only two other people like this and they both have ADD as well...