Debora Warner, 44, loves the machine that some runners love to hate. Last November, she founded the Mile High Run Club, New York City’s first treadmill studio, which specializes in indoor group running classes. With the ambiance and camaraderie of a spin class, her workouts do more than make you sweat. In the span of 28-, 45-, or 60-minutes, the hills, builds, and intervals are designed to take time off your PR.

Here, she gives us a taste of what a 28-minute class would entail. And although your treadmill probably doesn’t have flashing mood lights surrounding it, you can replicate the Mile High Run Club environment by turning up the bass and convincing a friend to run by your side.

“That’s the beauty of bringing a speed workout indoors to the treadmill,” says Warner. “Everyone is able to work at their individual training level, but you can still work together.”

Whether you’re running a 5K or marathon this season, or just looking to get a solid workout in on a chilly day, this treadmill routine will kick your training into high gear.

At Mile High Run Club, Warner uses the following level guidelines to instruct her students:

Level 1 = light effort (recovery pace)
Level 2 = moderate effort (marathon pace)
Level 3 = hard effort (10K, half marathon pace)
Level 4 = max effort (5K pace)

Start your 30-minute routine with a 5-minute warm-up at an easy pace. And then…

Hills
3 minutes at Level 2, 4% incline
1 minute at recovery Level 1, 0% incline
2 minutes at Level 2, 6% incline
1 minute at recovery Level 1, 0% incline
1 minute at Level 2, 8% incline
1 minute at recovery Level 1, 0% incline

Ladder
3 minutes at Level 2
3 minutes at Level 3
2 minutes recovery at Level 1
2 minutes at Level 2
2 minutes at Level 3
2 minutes recovery at Level 1
1 minute at Level 2
1 minute at Level 3

Take 5 minutes to do a nice, easy cooldown. Then stretch.