How do writers stay in shape?

For the first time tonight, after four or so years of (occasionally dedicated, mostly sporadic, never impressive attempts at) running, I think I finally experienced that endorphin rush that exercise enthusiasts never stop insisting exists. So I'm forced to conclude it hasn't been a sustained worldwide conspiracy from the beginning of time until now on the part of people who have nothing better to do with their time besides stay healthy and happy. Great!

Now I need to figure out how to make it happen again. I switched up my normal routine in a couple of ways -- including going at night, when I'm actually awake, instead of during the afternoon, when all sensible writers and other unemployed folk are enjoying a nice siesta. There was also an novel interlude with a stairclimbing machine that might have played a role.

No doubt it's all those endorphins making me overshare all this, but it actually does touch on a topic I wanted to cover: how do writers stay in shape? Lots of office workers spend their days sitting at a desk, but at least going to an office entails a more considerable geographic displacement than from bed to (in my case) couch. When the writing is going well, a trip to the gym seems like pure indulgence. I know that exercise is supposed to keep the brain working well, but it's so hard to always keep that in mind. (Especially, I suppose, when one hasn't been exercising. The ole memory starts getting rusty.)

I've been combing this great blog for ideas (sadly, it hasn't been updated in ages), but the top few entries mostly indicate the consumption of Benzedrine and whiskey. If you have any tried and true tips, please share.

I was almost going to include a faceless photo of a famous writer with a big belly in order to provoke a cruel and body-image-anguish-inducing guessing game, but that seems slightly mean, and also a bit time-consuming. Instead you get this picture of a StairMaster.