For a very long time, I exercised without the aid of an MP3 player. My reasons were many: I thought it would be distracting … thought it would be unsafe (when walking outdoors) … thought it would be too much hassle to remember to pack one more thing in my gym bag … thought it wouldn’t make any difference to my workouts.

Boy, was I wrong.

Five years ago, some of my best marathon buddies surprised me with the gift of an iPod, plus CDs of their favorite walking music.

So I loaded the CDs onto the iPod and hit the pavement.

Wow! I didn’t pay any attention to how much time I was out walking and instead eagerly awaited the next song and its tempo, enjoying the boost in energy the music gave me.

Then I used my iPod while on the treadmill. Suddenly I noticed how certain songs aligned with certain treadmill speeds. I realized I could make a whole playlist of songs whose tempo matched my usual speed — or my desired speed — and customize my workouts.

For several of my next treadmill sessions, I scribbled down songs and their corresponding speeds. Then I found websites that listed songs’ beats per minute, or BPM. That enabled me to match songs to treadmill/walking speeds and find songs that best worked for me. The next step: putting together a few different playlists of different lengths, including slower warm-up and cool-down time.

(As a fitness instructor, I now have a secret source of prearranged playlists: Several companies put together CDs geared to certain BPMs for certain types of exercise. To conform to copyright law, the CDs do not feature the original artists, but sometimes it’s hard to even tell.)

Much research has been done on whether music has a positive effect on one’s workout. Among the findings are these benefits:

• Reduced feelings of fatigue
• Increased feelings of mental motivation
• Increased endurance
• Improved motor coordination

The research results are varied in terms of measuring the exact effects — but it’s clear that choosing music that moves you can, well, help you move.

And beyond that, there are no rules! Choose music that you find motivating with no apologies. Guilty pleasures? Why not! Whatever you hear through your earbuds is your little secret. If it gives you a boost, that’s the point. Match the music to your mood — or your desired mood. I have a CD of heavy metal songs (like Metallica’s “Enter Sandman” and Pearl Jam’s “Even Flow”) for when I really need a kick in the pants to get going. I like to listen to Billy Idol’s “Greatest Hits” on the stationary bike. Sometimes dance music works best — favorites include C+C Music Factory’s “Gonna Make You Sweat” and Justin Timberlake’s “Sexy Back.”

Here is one of my most-used playlists, which I created for walking. It’s about an hour long, starts and ends at about 3.5 or 3.6 mph, and peaks at about 4.1 or 4.2 mph.

It’s a mix of a few songs from those original CDs from my race pals, some songs from instructor CDs, and a few tunes that caught my ear as having a good beat or feeling inspiring.

If you haven’t tried working out to music (separate from a group class, of course), give it a try and see if it works for you. Just press play! (And feel free to share your favorite workout tunes in the comments!)

Thanks to loyal WWJ reader Lauren Z. for this post idea!