Feeling a bit run down on your running training? Try reverse sprint intervals, a workout method that adds an unconventional challenge to high-intensity interval training (HIIT) on the road, trail, or treadmill. And no, we’re not talking about running backward.

Typically, in sprint interval training, you’ll run for a set amount of time and then rest, progressing your effort to getting faster and faster each interval. Or you might do something called a pyramid workout, where you ladder up to a top speed and then climb back down the ladder.

Reverse sprint intervals are basically only the second half of the pyramid. HIIT-style workouts that incorporate running, like Barry’s, will often incorporate this kind of interval training, so we asked personal trainer and Barry’s instructor Ianthe Mellors, CPT, for tips on how to put your HIIT running in reverse.

What are reverse sprint intervals?

Rather than progressing to faster and faster speeds, in reverse sprint intervals, you’ll start at your maximum effort and then ease off the gas a little bit with each interval.

“Reverse sprint intervals are intervals that begin at the highest intensity then decrease as the intervals are repeated,” Mellors says. “For example, the first interval is 10/10 effort, next 9/10, then 8/10, and so on.”

“It also allows the participant to work harder than they thought possible—they know the first one is the hardest, so they’re most recovered and not trying to conserve energy for later in the workout.” —Ianthe Mellors

What are the benefits of reverse sprint intervals?

Why would you want to climb back down the ladder rather than just go up? Reverse sprint intervals can be a great exercise in activating your recovery mode, as well as getting to know your energy and abilities.

“It teaches the participant to control their effort and energy and really focus on form,” Mellors says. “Working at the highest intensity at the beginning of the workout then pulling back requires the participant to try to recover and get out of flight or fight sooner.”

Putting your max effort at the beginning of your workout also allows you see what that looks like when you’re not already fatigued.

“It also allows the participant to work harder than they thought possible—they know the first one is the hardest, so they’re most recovered and not trying to conserve energy for later in the workout,” Mellors says.

How to do a reverse sprint interval HIIT workout.

1. Warm up to start

Because you’re starting at your maximum effort, ensuring your muscles are warm and your cardiovascular system is kicked into gear is even more important because you won’t be easing into the work!

“Always warm up before a HIIT workout and stretch after,” Mellors says. “You want your body to be ready for the demands you’re about to place on it then brought back to its resting state afterwards. For a warm up, your goal is to activate the muscles you’re about to use, mobilize your joints, and elevate your heart rate.”

Try this 8-minute warm-up to get in gear.

2. Pick your sprint and rest durations

How long do you think you can sustain your highest effort for? Pick your duration (say, 30 seconds), and then allow for a rest interval—during which you’ll lightly jog or walk—that’s twice as long as the work portion. So for 30 seconds of work, you’d recover for one minute.

3. Pick your locale

You can do a reverse sprint interval inside on a treadmill or out in the world. If you’re on a road or trail, “make sure you have a clear path so you can perform the interval continuously without having to worry about traffic,” Mellors says.

4. Put the pedal to the metal

Once your interval starts, begin running all out. For your next interval, shave off some of that speed and power, and continue doing that for each 30-second sprint.

“Your first interval [is a] 10/10 effort. Rest. Second interval 9/10 effort. Rest. Repeat until you get to 5/10 effort,” Mellors says.

Here are some tips for how to find your running pace and identify those efforts.

5. Repeat the ladder (if you want to!)

Once you ladder down to your 5/10 effort, you can choose to repeat the whole song and dance from the top one or two times more. Or not—totally up to you!

6. Don’t forget to cool down

Try bringing your heart rate back down with a walking cooldown.