If you ask us, no workout is complete without a killer playlist — and running is no exception. Whether you prefer the trails or the treadmill , the right songs can make the difference between a good run and great run. (No, that isn't just your addiction to pop talking.) Plus, music has actually been found to improve people's performance during cardio workouts. A 2009 study , for example, suggested that music helps us power through fatigue more easily. See, even science wants you to run for your life with Yeezy at full volume. We asked R29 staffers to share their favourite running songs, and they did not disappoint. This week, we've added new tracks from Katy Perry, Desiigner, and more. Below, we've rounded up some of the most motivational, energising tracks out there in one amazing playlist.