"Play around," advises Kolber. "Put two songs together with different tempos. Make one a little faster and one slower," and see how it affects your pace. If you tend to match your stride to the beat, she says, it's more important to choose rhythmic songs that will keep your cadence up.
4. Outsmart yourself. Kolber says she creates mixes with a strong, motivating tune every three or four songs, because that's when she tends to fade. Know yourself, she advises. Acknowledge your weak points and stay one step ahead of yourself.
"Right around 25 minutes, when you're just dying to get off, pop in some strong songs during that time to get you through," she says.
5. Make your playlists before you hit the gym. This can be a great stall tactic: Getting to the gym, waiting for your favorite treadmill to become available, then choosing the songs you want to listen to, one by one. You won't get the same workout if you're continually stopping to switch playlists or find a better song. Create your music mix before leaving the house, or, when you have some spare time, create a few workout music mixes to choose from.
6. Explore music. Everywhere from iTunes to Barnes and Noble, you can listen before you buy. And single songs can be purchased for less than a dollar online. It's a great opportunity to check out new artists or even genres of music you're curious about, says Kolber. Just because you don't like country doesn't mean you won't like Lyle Lovett. If you've seen Riverdance four times, download "Countess Cathleen" and see if it inspires you to push yourself that extra five minutes. Or try trading off favorites with friends. Make each other a CD of your favorites, and take that to a workout.
7. Find remixes. Popular music is overplayed on the radio, and can get stale. If you really love to play songs you can sing to, Kolber recommends downloading remixed versions of your favorites. They are usually longer and have a lot more beat behind them (which is great for a workout). On Woelfel's most recent playlists are remixes of "Rocket Man" by Elton John and "Killer 2005" by Seal. Or try using a popular song from a different decade, says Woelfel, like "Good Vibrations" by Marky Mark or Michael Jackson's "Working Day and Night" and putting them in the same playlist with the new Christina Aguilera or Black Eyed Peas.