Let's face it: working out can be a monotonous task sometimes. Because it's mostly the same routine day after day, our brains naturally get tired of it, which can decrease the effort we put into a workout. One of the best ways to combat this kind of slowdown is through the use of music. Thanks to the shuffle feature found on most MP3 players, your workouts can now become unpredictable on an auditory level. When we don't know what song is coming next, our brains are more entertained. That means proper use of shuffle can actually increase your productivity.