I had to laugh a little at "their impact on performance remains unexamined" as the bicycle touring crowd has used plain boiled potatoes as a common fueling snack for as long as I can remember. When I did the Seattle-to-Portland ride 15 or so years ago all of the aid stations had tubs of them to hand out. This study seems to be yet another instance of Taleb's "lecturing birds how to fly" phenomenon.