They exercise is good for many things, creativity being one of them. I do the occasional exercise in the form of mountain biking. Preferably, I would roam around on single tracks all the time, but time constraints often limit me to loop around Tel Aviv, close to my home.

And here is the weird thing that is happening to me: every time at about the same time/distance in the run, I get some pretty useful ideas for design problems I am struggling with. I started to notice, because the choice of tracks around my home is not that big, the weather in Israel is pretty much the same every day, so these bike runs happen at more or less the exact same circumstances.

So, the inspiration comes 40 minutes or about 16 km in. Maybe it is this exact amount of exercise you need, or there is something about that specific location....