Nike is doing a great job of finding the most incredible athlete stories to feature in its "Unlimited" campaign. After the transgender duathlete and the 86-year-old "Iron Nun" comes Kyle Maynard, a quadruple amputee who has climbed Mount Kilimanjaro without prosthetics.

As with the nun spot, an incredulous narrator lends a light-hearted tone -- "Dude, that's not funny. You're on top of a mountain" -- although viewers will still marvel at what Maynard, a 30-year-old author and motivational speaker, is able to achieve. Once again, Wieden & Kennedy Portland is responsible.