One of the best things about running is the low barrier to entry—throw on some sneakers and you’re ready to go. But as you start to increase your mileage, whether you’re training for the New York City Marathon, a Rock 'n' Roll half, or a local 10k, you start to realize that what you wear, how you fuel, and the accessories you carry are all critical to your success—in other words, there comes a time when you'll want to upgrade your road running shoes or swap out that old gym shirt for a moisture-wicking option.