"Jimmy Buffett. It's all around feel-good music and takes your mind off what you're doing," Carter said.

While many can't work out with some tunes going, Carter can get it done either way. And rather than using them for motivation, he likes Buffett for relaxing.

"I use it to take my mind off it," he said. "If you sit here and stare at (the treadmill), then you tire easier. So it helps you relax, take your mind off of it and just go at it."

"I listen to a pretty eclectic mix of stuff," Daniel Kilpatrick said. "Generally, it's electronic rock and some hip-hop."

Melissa Lindley teaches aerobics and thinks a variety of music is helpful.

"I like to change it up because it makes a big difference in where they are," Lindley said. "Most of the people that come to aerobics classes do the same thing week after week. When you change the music, it changes the whole mood and momentum. And some people can push harder."

Kilpatrick downloads songs to his mp3 player in order to customize his music for workouts.

"I had to find a particular sport headphone to go with it because the heavy headphones are uncomfortable and the foam gets sweaty," he said. "I like the ear buds because they don't get sweaty and aren't heavy."

But there are some people who don't like anything in the ears. Cleveland Street YMCA employee Brian Ferguson said it's simply annoying, though he doesn't mind if tunes are playing over the stereo system.

"To me it's more of an aggravation to have it on my body, especially running on the treadmill or working out. It's more of a nuisance. There's just something about it that drives me nuts."