After a full week of staring at a screen and sitting too much (I alternate between standing/sitting desks all day) and typing, the last thing in the world that I want to do is more of that. Which is unfortunate, because there are numerous fun programming projects that I'm itching to do.
So I play music and make elaborate chalk art with my kid and garden and ride my bike like a madman. And I suspect that I'm better for it. (Though I'd probably be better at my day job if I were doing those side projects.)