The workout mix: a time-honored tradition of fitness enthusiasts in gyms all across the world. Few things can inspire an athlete to push harder, to work longer … or to start a fistfight with other gym-goers better than a carefully selected list of songs intended to get the heart pumping.

At some point, years ago, running wasn’t “cardio,” it was just what got you to the other end of the playground faster. Back when food was food and we never worried about the caloric content. Back when we tapped our pencils on our desks, impatiently waiting for recess to start so we could stretch our legs, our lungs, and our imaginations.

Eventually, our days grow fuller, more regimented, and “fun” becomes a vague concept we associate with faraway tropical locations or with the few fleeting days a year we’re able to sneak away from our jobs, responsibilities, and social lives to gallivant around in the woods with a rifle or a pack. We stop running across playgrounds and start jogging around the neighborhood. We stop tapping our pens on the desk in anticipation for recess. We are now looking at the clock and pining for the blessed reprieve of our beds… “only ten more hours to go, and I can finally get some sleep.”

During that one hour a day or so that we grant ourselves the freedom in the gym, we devote it to counting things. Four more reps, 10 more minutes, 30 more pounds. The only thing that can save us from seeing this part of our day as a function of the adult work-life we’ve cultivated is our choice in tunes blasting from our stereos, headphones or speakers.

The right beat, the right guitar riff, the right combination of vocals and emotion pouring out of Spotify, a CD, or if you’re like some the dudes I work with, a seasoned old cassette tape, can take even the most arduous workout and turn it into a romp across the playground. It can take the salty old man that stumbled into the dimly lit, damp, cold garage beneath my kitchen and turn him into a light on his feet powerhouse — eager to get under the next bar, and antsy at the idea of improving.

What makes a good playlist then? Well, like so much of the fitness racket, it all comes down to personal preference. What gets my blood pumping might not work for you. In fact, I’d be willing to bet that most of you would probably laugh at some of the songs I use to put me in the right state of mind (especially on heavy-weight, very low rep days). Like so many lifters that came before me, my moto-mix seemed to stop evolving somewhere around my senior year in high school, and while lots of songs have been added and removed since, the staples remain the same.

But then, maybe that’s why it works.

The music that drives you has to connect on a deeper level than simply making your toe tap. “Uptown Funk” by Bruno Mars is one of my wife’s favorite songs, and I’d be lying if I said it doesn’t make you want to move your feet, but I’ve never heard it come on the radio and felt the overwhelming urge to do deadlifts.

“Cowboys from Hell” by Pantera, however, tends to have that effect on me.

You probably already know which songs can nudge you off the couch and into your running shoes, and if you’ve spent some time in the kind of dingy, hangar gyms I’ve loved all my life, you’ve probably been subjected to the playlists of some others… that just didn’t make any damn sense to you.

“Who the hell works out listening to Pink Floyd!?” I’ve shouted from beneath a 200 pound Marine, hammer-fisting my face from half guard. You know you’re music preferences are strong when “Comfortably Numb” is a more pressing issue to address than the guy trying to feed you your mouthguard.

The right song, at the right time, can elevate your workout, your state of mind, and your spirits for the rest of the day. The right workout playlist can turn an arduous workout into the best part of your day. That’s the power of music: nothing more than vibrations of air molecules, manifesting themselves in added plates, added reps and added progress.

In my opinion, the workout list is a pretty private endeavor: I can’t be worried about what you might think of a song and how well it’ll motivate me if I’m trying to get anywhere good. I prefer headphones over speakers, so I don’t have to defend my choices or put up with yours, and to be honest sometimes I am even a little embarrassed about what’s working for me on a given week.

A few years ago, while lifting in a Workout World in Worcester, Massachusetts, I was approached by a young guy asking for some advice. Despite wearing my headphones and maintaining a pretty impressive resting bitch face, some folks still think the time between sets is best used for talking shop. I tried to be polite, but concise, in my responses.

“One last question — what are you listening to on there? I wanna get on your program!” The flattering dude gave one last jab at a conversation.

“Slayer,” I replied, hitting play again on my Harry Potter audiobook.

It’s all about whatever works, guys.

I’ll see you on the blacktop.

This article was written by Alex Hollings.