National Geographic has always been a pillar of learning, used to prop up bookcases in student apartments throughout the world. But gone (almost) are the days of the print edition, and the resulting overstocked shelves of Goodwill stores. The content, too, has altered, so that alongside the standard fare of paleontology and volcanology, readers can now learn about their inner geography. Most recently, I was heartened (in the literal sense) to read an article on VO2max, in which this metric was cited as “the strongest predictor of cardiovascular and all-cause mortality”.