Imagine heading to the top of the Stratosphere without using the elevator. That’s 108 flights, 1,455 stairs and, if you’re Mike Schramm, 8 minutes and 31 seconds of pure cardiovascular perseverance.

Schramm is the top local qualifier going into the annual Scale the Strat stair race benefitting the American Lung Association, and on March 2, close to 600 brave souls will put their lungs and legs to the test as they join him and other elite competitors climbing the casino’s iconic tower.

Schramm’s first crack at the Strat came five years ago when his employer, United Healthcare, fielded a team for the race. A veteran marathoner, Schramm was a natural pick, but on race day he learned an important lesson: running and stair climbing are not the same thing. Not even—deep breath—close.

“When you do the stair climb, it only takes between 7 and 25 minutes, but within 60 seconds of [starting] the stair climb you are at your maximum heart rate and your breathing is very labored,” Schramm says. “If you’re a runner, you can ease into it or you can get your heart rate down and keep that pace going for however many miles you want to do. But with this, you’re at maximum heart rate and there’s nothing your can really do about it except stop. As long as you keep climbing the stairs your heart rate’s going to stay right there.”

Schramm learned this lesson about two minutes into his first Scale the Strat. He was in the stairwell, mid-race and he wanted to quit. “I said, That’s it. I’m done. I don’t even want to do this. … I’m just going to walk up the rest of these stairs and just be done with this. I’ll never do this again; this is crazy.”

But he finished. And when he got to the top, Schramm learned he had finished fifth. “I said, You know what? Everybody goes through this experience. It was just much harder than I thought it was going to be, but everybody goes through that challenge.”

Now, as Scale the Strat celebrates its fifth anniversary, Schramm has some advice for all those rookies taking on the tower for the first time. 1. Use the handrails to pull yourself up each flight like the pros do. 2. Start slow.

And when you start to feel defeated, just think of Schramm: huffing, puffing and gutting his way toward a personal record a few flights above your head.