If you cycle, you’re fit, right? Riding a bike is not a natural human movement, and cycling a lot with little other movement endeavors has the components of a junk-food movement diet. Let’s look beyond the few single nutrients that biking provides and explore a more nutritious movement diet—because doing the same thing over and over again means you are missing a whole spectrum of movement nutrients. Katy answers questions about bone density, kids and bikes, and the biological tax of bicycles.