Why are so many athletes opting to run 26.2 miles? Vox's Joe Posner explains the marathon from inside a mass of 50,000 other runners. Subscribe to our channel! http://www.youtube.com/subscription_center?add_user=voxdotcom Vox.com is news website that helps you cut through the noise and understand what's really driving the events in the headlines. Check out http://www.vox.com to get up to speed on everything from Kurdistan to the Kim Kardashian app. Check out our full video catalog: youtube.com/voxdotcom/videos Follow Vox on Twitter: https://twitter.com/voxdotcom Or on Facebook: https://www.facebook.com/Vox