People tend to view running as a "green" sport because it is light on equipment and doesn't usually require the use of a car to get you somewhere. It's true that running has a lot going for it, however, the apparel that runners use can take a very big toll on the environment. According to a 2008 study by Runner's World, the average runner goes through three pairs of shoes each year, which translates to 430 lbs of CO2 used in manufacturing and shipping. What's worse is that the materials used in running shoes can take up to a thousand years to biodegrade in a landfill. By choosing eco-friendly running shoes and apparel, you can drastically reduce the impact your sport has on the environment. Check out these ideas to help you have your greenest run yet!