It’s a perennial argument in running: music or not? This post assumes you’re already in the first camp. If you don’t like running to music, I’m not going to try to convince you otherwise.

If you’re a runner, one of the most important things to pay attention to you is your cadence, which is the tempo at which your feet hit the ground as you run. Most experts agree that a cadence between 170 and 180 beats per minute (BPM) is best for optimal performance during a race. According to physiotherapist Blaise Dubois, as quoted on Competitor.com, “170 and higher is ideal, but ‘ideal’ is slightly different for each person.” Many running coaches suggest experimenting with different cadences within that upper range until you find one that works best for you.

So how do you get your cadence up and keep it there? Many runners use tempo music as a sort of metronome for their feet. If you’re a musical person, it’s actually hard not to fall into step with whatever music happens to be playing in your headphones. For myself, I prefer the hour-long tracks put together by Steve Boyett of PodRunner.com. This works for me, but I know other people find these tempo tracks monotonous.

Many runners create playlists of their favorite running music. There’s a problem, though. What if you really like a song that was recorded at 157 BPM, but you want to maintain a cadence of 180? Simple: change the tempo of the music.

Disclaimer

It goes without saying that you should only mess with the tempo of music you have legally purchased and/or have legal rights to. If you’re worried about the legality of this process, check with a smart person who knows about music rights (like a lawyer) first.

For my example here, I’ll be using a track called “Creative Minds” that I downloaded from the royalty-free music site Bensound.com. You can listen to it below. This song was released under the Creative Commons license. If you like it, visit the site for more.

Free Software

Unless you’re a professional sound engineer with a full studio already set up, you’ll need to get some audio software. Luckily, there’s a great program out there called Audacity—and it’s 100-percent free. Here’s how to get what you need:

1. Download and install Audacity. You’ll find versions for Windows, Mac OS, and GNU/Linux.
2. Download and install the LAME MP3 Encoder. Go to this page to find the installer. They keep moving the link around, so you kind of have to hunt for it on the page. Because of license restrictions, Audacity doesn’t come with the native ability to export an MP3 file, but the free LAME MP3 Encoder adds this feature.

Once you have those two free tools installed, you have all the tools required to mess with the tempo of your music.

Determining Track Tempo

So how do you figure out the actual cadence of a given song? Well, there are a couple of different ways:

1. Check an online database. There are several sites (such as songbpm.com or getsongbpm.com) that provide the tempos of thousands of popular songs. It’s not an exact science. For example, one site tells me Billy Idol’s “White Wedding” is 148 BPM, while the other one tells me it’s 147. But … close enough for jazz, right?
2. Use a tap/click petronome. Alternatively, you can play the song out loud and tap/click to the beat. I’ve found a few websites (two of my favorites are all8.com and beatsperminuteonline.com) that let you do this for free. The longer you tap or click, the more accurate the measurement. It usually takes 20-30 seconds to get a good average of a song’s tempo.
3. Use a metronome app. I have an app on my phone called Micro Metronome that does the same thing the metronome websites do. Search in Google Play or the Apple Store for a metronome app that has a tap feature, and you’ll be all set.

According to my highly refined skill of tapping the space bar along with the beat, the song “Creative Minds” is 166 beats per minute. That’s close enough to serve as running music, but not quite fast enough for my marathon pace.

Opening and Editing Your Track

If you know the tempo of your existing track, it’s now time to edit. Here’s how:

1. Open Audacity. The program will launch a window with tools at the top and bottom and a blank space in between.
   
2. Click the File menu and select Open. This opens a dialog box asking you to locate the file of running music you want to edit.
3. Select your file and click the Open button. In this case, I chose “bensound-creativeminds.mp3.”
4. Audacity will import the file into the editor. You should now see your track as a stereo waveform in Audacity. At this point you could do a LOT of things to your sound file. But we only want to change the tempo—nothing else.
   
5. If it’s not already selected, select the Selection Tool by clicking the button directly to the right of the red Record button. The icon looks like a capital I. Your cursor (within the Audacity program) should look just like the icon.
6. Click somewhere on the waveform area of the track. It doesn’t matter where.
7. Select the entire track by pulling down the Select menu and clicking on Select All. You can also use the shortcut Ctrl-A (or Cmd-A on a Mac). You’ll notice that the waveform changes color.
8. Click the Effect menu and select Change Tempo… This opens Audacity’s Change Tempo dialog box. (Note: do not select Change Speed…! If you do this, the pitches of the music will change along with the speed. This can result in a Chipmunks-type effect if you speed up a track containing vocals!)
   
9. Enter the current tempo of the track in the “from” field, and the target tempo into the “to” field. I chose 180 as my target tempo. The other settings will automatically update to let you know what the percent change is, and how this will affect the length of the song.
10. Make sure “Use high quality stretching (slow)” is selected. Then click the OK button.
11. A progress window will open as Audacity processes your tempo change. It may take a few minutes, depending on the length of your track.
12. Once it’s done, you can listen to your edited track by using the playback controls at the top, left corner of the Audacity window. You can listen to my tempo-shifted version of “Creative Minds” below:
    
13. To save your re-tempoed track, click the File menu and hover over Save Other to show the sub-menu. Choose Export as MP3 (or one of the other options, if you prefer another format).
14. An Export Audio dialog will open. You can edit the filename (I like to add “-180bpm” or something similar to indicate a track has been modified) and play with the Format Options below. For running music, any quality setting 2 or higher should be sufficient.
    
15. Click the Save button. At this point you have the option of editing the Metadata Tags (which help your music player display information about your track). At the very least, enter the Artist Name, Track Title, Album Title and Genre. I always use the Genre “Running Music” to make it easy to select running tracks on my phone.
16. Click the OK button and you’re done. You can safely close Audacity (unless you want to edit more tracks). Don’t bother saving the project, since you’ve already exported it as an MP3.

For comparison, here is the original version of “Creative Minds”:

And here is the modified version at my running cadence:

You’ll notice that the pitch of the music hasn’t changed at all. (That’s why you choose Change Tempo… instead of Change Speed…) Also, the length of the song went from 2:27 to 2:16. I can now load this onto my phone and run to it, and it’ll help me keep my 180-BPM cadence.

Final Notes

Be careful as you select tracks to change the tempo of in this way. If you take a song from, say, 100 BPM and speed it up to 175 BPM, it’s going to sound really weird.

Also, remember that 90 BPM is the same as 180 BPM—you just take two steps for each beat. A 100-BPM song might not work at 180, but it might not sound terrible at a tempo of 90.

Don’t forget to share this post with all your running friends!