"This workout is a blazing dose of cardio," says group fitness pro Amy Dixon, a cocreator of the killer new Firestarter class at Equinox in Los Angeles, who designed the sample routine below. The class has you push for 15, then 30, then 45 seconds at high intensity—then back down the "pyramid" for 45, 30, and 15 seconds—with just 15 seconds of rest in between.
"Because you never fully recover between sets, you are working at a level of intensity that will make you fitter and improve your performance," Dixon says. Plus, you'll burn big calories along the way—and post-workout too. (Here's more on how to maximize rest time during HIIT.)
Each pyramid (think of it as a mini circuit) contains two alternating exercises that strategically target the body in different ways. That means you won't be so exhausted during each push interval that you can't give it your all.
You'll crank out three pyramids total. After each, you should feel like you went hard enough that you want to stop and completely recover. Instead, you'll do two minutes at a slow-jog pace before moving on to the next pyramid.
"Research shows that active recoveries ranging from two to four minutes are the sweet spot for getting your body ready to tackle another interval at such a high intensity," Dixon explains. (Correct active recovery is important on rest days too, FYI.) By the end of this session, every last muscle will have been whipped into shape. And your metabolism? It will be on fire.
You'll need: A small step to scale moves up or down (optional)
How it works: Start with the warm-up. Then complete each pyramid once, alternating between exercises A and B for varying time intervals with 15 seconds of rest after each interval. After finishing each pyramid, recover for 2 minutes at an easy to moderate intensity by jogging forward and backward (or jogging for 1 minute, then performing skaters for 1 minute).
Warm-up: Do 30 seconds each of alternating side-to-side squats (step right leg out to right, toes facing forward, and bend right knee to lower into squat with left leg straight; return to starting position, switch sides, and repeat), triceps push-ups, alternating forward folds (touch fingers to floor if possible) and hip extensions (stand, arching back slightly), and alternating butt kicks and high knees. Repeat.
Spider Lunge Pledge
A. Start on floor in plank on palms.
B. Jump left leg forward to the outside of left hand as you touch left hand to right shoulder.
C. Return left palm to starting position, then switch legs (lunge left leg back, right leg forward to outside of right hand) and bring right hand to left shoulder. Continue alternating as quickly as possible.
SCALE DOWN: Do the entire sequence with hands on a small step instead of floor.
A. Stand with feet farther than hip-width apart.
B. Tap left foot in toward midline of body, then immediately step it out to starting position. Switch sides; repeat.
C. Continue, pumping arms as if you were running and moving as quickly as possible.
SCALE UP: Start by straddling your step. Tap left foot atop step, then immediately place foot back down to the left side of step as you tap right foot atop step. Continue alternating.
Standing Long Jump
A. Stand with feet farther than hip-width apart.
B. Jump forward as far as possible, landing with soft knees.
C. Shuffle back to starting position, then perform a tuck jump.
D. Repeat, moving as quickly as possible.
SCALE DOWN: Instead of tuck jump, alternate bringing left and then right knee toward chest, touching hands to knee.
SCALE UP: Kick butt as you jump forward.
A. From standing, step left foot out to the left.
B. Jump right foot to meet left and tap toes to floor. Drive both arms back as you land.
C. Switch sides; repeat. Continue alternating as quickly as possible.
SCALE UP: Fold forward from standing, knees slightly bent, and place hands on step, shoulders directly over wrists and feet just to the left of the step. Jump up, placing body weight into hands and hopping over step to the right side. Repeat, moving as quickly as possible.
A. Stand with feet shoulder-width apart, arms bent, hands by chin.
B. Jump as you kick left foot forward, then switch, kicking right foot forward after landing.
C. Continue alternating as quickly as possible.
SCALE DOWN: Instead of jumping, step forward, snapping kick out to front. Return to starting position. Switch sides and repeat.
Quarter Switch to Double Lunge
A. Stand with feet hip-width apart, knees slightly bent.
B. Jump up, doing a quarter turn to left, landing with soft knees, then jump back to starting position.
C. Jump up, landing in a lunge with left leg forward, bending both knees to 90 degrees. Repeat lunge jump, switching legs midair to land with right leg forward.
D. Return to starting position. Repeat sequence, turning to the right. Continue, moving as quickly as possible.