The right playlist can make or break your workout.

We've all been that person fiddling with our iPhone or other music player while on the treadmill. It might be worth the temporary lack of focus to change the song to something faster to pick up our pace, but it is still a hassle.

A new app for iOS called Cruise Control bumps up the speed of your music or slows it down based on how fast you're moving. You can set your target pace in the app, and your music will adjust to that desired pace.

There are four ways to use the app. First, you can just launch it and start running. Your music will adjust to your speed. Second, you can chose your target speed and music will match that pace. Stay on your pace by running in-sync with the playlist. The developers say the average pacing error is less than 1%. The third way to use it is to select a target heart rate (you'll need an ANT+ or Bluetooth Smart heart rate monitor). Again, match your steps to the playlist and the music will get slower or faster based on what your target heart rate is set at. The developers write that lab tests show, on average, the heart rate is within 2 beats per minute of the target. The final way to use Cruise Control is to pick a target stride rate, then all of your songs will adjust to match that pace.

The patent-pending algorithms used to match your tunes with your pace were developed by researchers from the Locomotion Lab at Simon Fraser University through a combination of human experiments and control theory.

SEE ALSO: 10 Motivational Apps for Runners

Need more songs on your device? You can visit the app developer's website at cruisecontrolrun.com to get some playlist ideas — you'll be directed to buy the songs on iTunes.

Cruise Control costs $4.99 in the iTunes store.

Would an app like this help you avoid breaking your stride to change the song on your music player? Tell us in the comments.

Photo courtesy of iStockphoto, blublaf