Gunnar Petersen smiling at camera

This Full Body HIIT Circuit Will Push You to Your Limit

Gunnar Petersen’s go-to HIIT workout will slice workout time and hammer your entire body.

When celebrity trainer Gunnar Petersen isn’t noshing on Reese’s peanut butter cups, he rounds things out with a punishing HIIT session.

As Chief of Athletics at F45, he’s a big fan of high-effort workouts that yield the same benefits in less time. “By using your session judiciously, you can have the rest of your day back to tackle your responsibilities,” Petersen says.

His secret? HIIT workouts that work the biggest muscle groups in your body, and push your cardio and strength to the limit. If you’re looking to maximize your fitness and time, his eight-move “HIIT and Run” routine fits the bill. Here’s the workout.

How It Works

Petersen’s rigorous HIIT session involves eight different exercises—some taxing your cardiovascular system like all-out pushes on the fan bike and treadmill, and others challenging your functional strength like medicine ball lifts and slams.

He utilizes a range of implements to achieve his full body workout, including a fan bike, rowing machine, battle ropes, inertia wave, medicine balls, and a treadmill. The result: a demanding HIIT circuit that will put your fitness to the test.


Why It Works

Most HIIT sessions involve one piece of cardio equipment. What makes Petersen’s HIIT workout unique is he makes the most of the equipment on the gym floor. By doing so, his routine builds functional fitness through different ranges of motion and modes, resulting in gains for your fitness and everyday activities.

He packs the exercises together in a quick and effective circuit that will leave you totally spent. His goal: to maximize effort and time. By cutting rest, he simultaneously stacks the load on the muscles and cardiovascular system. Make the most of every second of his grueling routine, and you can be in and out of the gym in under 30 minutes.

The Workout

Ready to move? Follow Petersen through his crushing “HIIT and Run” workout (and don’t forget the partner sled pulls to clean up shop).

Full Body HIIT Circuit: 

  • Air Bike Sprint
  • All-Out Row
  • Battle Ropes
  • Inertia Wave
  • Med Ball Slam
  • Wall Ball Throw
  • Treadmill Run

Petersen didn’t share the time breakdown which means you can adjust the work and rest time to make it harder or easier or cut down on time if you’re running short. We suggest aiming for 45 seconds of work to 15 seconds of rest for each exercise in the circuit.

After completing the full circuit, rest a minimum of 90 seconds. The rest will give you the energy you need to put in your best effort during each round of work.

You can repeat the workout as few or as many times as you’d like. One round of the circuit can be completed in eight minutes. We’d recommend shooting for three to four total rounds of the circuit to build fatigue, but maintain quality movement (which will start to break down as you get tired).

Air Bike Sprint

Petersen starts his workout with an all-out push on the fan bike. Fan bikes are a great full body workout because unlike a classic stationary bike they work your upper body. Fan resistance is progressive so the harder you push, the harder it feels—making this exercise a perfect (and killer) way to kick off this circuit. As you push, focus on keeping your core tight. This will protect your spine, and help your arms and legs push harder, too.

All-Out Row

If the fan bike didn’t already push you over the edge, Petersen follows it up with a sprint on the rowing machine. Rowing is one of the most challenging cardio workouts you can do because it works approximately 86 percent of the muscles in your body. With each stroke, focus on pushing with your legs first, and then follow through with the core and arms.

Battle Ropes

Battle ropes are one of the most effective pieces of gear to diversify your fitness routine. Petersen uses ropes in this workout to keep your heart rate up, get your arms working independently, and keep your muscles under tension for an extended period. He might make it look easy, but after 10 seconds your arms will be toast. To master this exercise, focus on core stability, using your arms to muscle this move.

Inertia Wave

Next up, Petersen uses Gronk’s Inertia Wave to double down on the core, and keep your heart rate spiked. The Inertia Wave acts like battle ropes to work your body unilaterally (or on one side at a time), but you can adjust the tension by standing closer or further away. Bonus: Petersen adds a squat jump in between waves, demanding full body power and coordination.

Medicine Ball Pickup

Petersen’s medicine ball pickup is a move you likely complete during everyday activities—picking up the laundry basket, carrying groceries, or doing yard work. We love that his variation involves picking the medicine ball up to shoulder height which means your quads, hamstrings, glutes, core, back, and arms are all involved in the equation. Fight to keep your chest up as you squat to reach for the ball and push it over your shoulder.

Medicine Ball Throw

His next medicine ball variation involves a two-step side shuffle back and forth, and a rotational med ball slam into the wall, followed by a pivot to repeat on the other side. This move is all about power and speed, but before you put all of your force into it, slow down to practice your footwork and focus on the anti-rotation of your core—both key components to perfecting this move.

Treadmill Run

Whatever is left in the tank, Petersen depletes with an all-out treadmill effort. The treadmill he’s using is manual, meaning he’s powering the belt with his own force. Manual treadmills are perfect for HIIT workouts because rather than relying on the treadmill belt to keep your moving to the finish line, it’s up to you to keep it going.