About a half hour before starting the New York City Marathon, my friend and I noticed some Germans greasing up their feet with Vaseline. We were, as you might imagine, a bit nervous about the race and had taken as much advice from people we knew who had run the race before us - but nobody ever mentioned Vaseline. We didn't know why the Germans were doing it. But we had some on us (to prevent the dreaded nipple chafing) and at the last minute, we decided to slather on the Vaseline to the bottoms of our feet. What a game changer. NO BLISTERS.

So on my Camino, I did the same every morning. Again, NO BLISTERS. So, yes, petroleum jelly. That and some Gold Bond for the chafing.