I believe that this process really helped me save my sanity during that time of extended mental stress. I could literally air our my brain, and also get some mild physical activity after sitting in the library all day. I tried really hard not to think about my thesis, but just to take in the scenery, the light, the wind. Sometimes it rained. It was really healthy.
In contrast, I remember a former co-worker telling me about a road trip they once did. I think it was in Arizona, but I might be wrong. Anyway, after driving for many hours, they decided to take a break and just to walk down the road for a few minutes before hitting the road again.
So they pulled over and started walking. Sure enough, in no time, they get stopped by the cops who inquire what the heck the are doing! They weren't walking on the road or in any otherwise dangerous fashion -- but apparently in that area, just being out and about on foot was enough of a reason to be considered suspicious. :-)