Mark Sisson — athlete, primal blueprint architect, health expert, and awesomely fit at 50-something blogger at — has informed countless numbers of people about how to have a healthier, happier lifestyle. He’s also informed more people about Vibram FiveFingers than virtually anyone via his informative video on beach sprints and “indigenous people squats:”

It goes without saying that Mark is on the short list of people I’d like to complete the birthday shoes interview. And if you’re looking for other barefoot alternatives (other than VFFs, that is), be sure to check out Mark’s most recent post on that subject.