Nearly every runner has experienced that all-too-brief, magical sweet spot where the music matches the beat, the legs stop aching, and plodding along feels more like flying. For recreational jogger Josh Leider, that perfect moment came midway through Eminem’s “Lose Yourself,” during a short run in Spring 2012. Instead of just hitting repeat like the rest of us, he wondered what would happen if his music library were organized so every song matched his pace. This May, Leider and his team launched TempoRun, an app for iOS that organizes music by tempo.

TempoRun from Scott Wasserman on Vimeo.

What’s the Deal?

After his euphoric Marshall Mathers-fueled run, Leider called up Benny Ebert-Zavos, a dedicated marathoner and fellow Michigan State alum. The two friends reached out to MSU student developers to refine their idea and get a working prototype. In the course of just a few months, they joined MSU’s “The Hatch” incubator, presented at South by Southwest, and won numerous local entrepreneurial pitch contests. After a few more months of tweaking, TempoRun launched their brand-new app on May 17.

The app categorizes a smartphone’s existing library into tempo categories from 1 (slooooow mo) to 10 (watch out, Usain Bolt!). Because music is arranged by beats per minute, it’s possible to rev up a run simply by switching from a more relaxed tempo to a speedier oneEffects+of+synchronous+music+on+treadmill+running+among+elite+triathletes.+Terry+PC,+Karageorghis+CI,+Saha+AM,+D’AUria+S.+Department+of+Psychology,+University+of+Southern+Queensland,+Australia.+Journal+of+Science+and+Medicine+in+Sport.+2012+January;+15(1):52-7.. Runners can also enter their preferred genre and tempo into SoundCloud (a separate login is necessary) to listen to radio through the app instead of their own music library. Currently, there’s no social aspect, but Ebert-Zavos explained that he’d love to create a way for users to share their playlists (and thus their workouts) in the near future.

According to Ebert-Zavos, the company’s “chief running officer,” TempoRun makes it easy for runners to find their own “sweet spot.” TempoRun’s level 6 or 7 (depending on the runner’s body and level of physical activity) is around 180 beats per minute. This specific pace encourages a midfoot strike, which many running experts and researchers believe is a very economical (a.k.a. efficient and fluid) form of running.

Is It Legit?

Yes, though it’s not without its constraints. While the app (and its team) is young, they’ve scored some impressive achievements after just one year. The team is hardly resting on its laurels, though, and is currently working on a calibration system so runners can customize the tempo runs to fit their own stride.

When I tested out the app on my afternoon jog, I found it a bit tricky when first gauging which tempo matched my natural pace. After a bit of fiddling, I felt comfortable at a 6. The overall experience made running more convenient, but my music library is relatively small (only 300 songs, and most of them levels 1, 2, or 3), so I could only listen to a few songs in the correct tempo category. The app would definitely benefit from a calibration system that sensed the runner’s pace and selected the correct tempo of music for them. That would save users five minutes of each jog fiddling with music and adjusting his or her stride.

According to Ebert-Zavos, TempoRun hopes to someday integrate with popular Internet radio companies like Pandora and Spotify, as well as collaborate with musicians and running shoe companies. Ebert-Zavos also wants to showcase the app at popular races and introduce it to the running community at those events. He sees TempoRun as both a way for runners to discover new music and a technology that makes running easier and more fun for everyone.

While I think the TempoRun app could use a few more technical tweaks to make it more user-friendly (a larger, more popular Internet radio partner would also help), it does its stated job of syncing music to running pace very well. Now I just need to beef up my iTunes playlist!

The TempoRun app is available for iOS via the iTunes App Store for $3.