Running Your First Marathon? A Running Coach Shares What to Expect

"Many first-time marathoners make the mistake of wearing their regular gym shoes to start running," Roberto said. You'll want a shoe that's designed specifically for running to prevent injury, as most training shoes aren't made for running and vice versa. Instead of just wearing any ol' shoe for your runs, Roberto recommended visiting a specialty running store to get a gait analysis — a running assessment that identifies biomechanical abnormalities and how your foot strikes the ground — to find the best style of shoe for your foot.