Actor Jordana Brewster is no newbie to the big screen-or to the gym. The Fast & Furious star has been working the Hollywood circuit since 1995, and she's also been working with celebrity trainer Harley Pasternak for more than a decade.

Throughout the years, Pasternak, who has trained Ariana Grande, Lady Gaga, Julianne Hough and Jessica Simpson, among other celebs, has given us glimpses of just how hard Brewster works during their sweat sessions (see here, here, here, and here for recent examples) . On Saturday, he shared even more evidence of Brewster's dedication in an Instagram video of her cranking out a classic (yet seriously challenging) lower-body move: the jump lunge.

You can check out the move, via @harleypasternak, here:

"I am a huge fan [of jump lunges]," Ashley Walter, Chicago-based certified personal trainer, tells SELF. "[They] strengthen your lower body, improve your balance, and challenge your core muscles."

The jump lunge is a great exercise for a number of reasons. For starters, it provides all of the lower-body strength benefits of a regular lunge-and then some.

When performing a jump lunge, , including the quads, glutes, hamstrings, and calves, Stephanie Mansour, Chicago-based certified personal trainer, tells SELF.

You’ll also work your core—specifically your transverse abdominis (the deepest ab muscle that wraps around your sides and spine) and rectus abdominis (what you think of when you think "abs")—as well as the stabilizing muscles around your hips, she adds. Core strength is required for standard lunges too, but it’s even more important with jump lunges to “stabilize the hips and upper body throughout the movement,” explains Walter.

In other words, jump lunges are basically a tougher, more challenging version of standard lunges, with extra core and hip stabilization work thrown in, too.

The plyometric element of the jump lunge makes this move a stellar cardio, balance, agility , power, speed, and coordination challenge.

The jumps are what really happens in the ante of this move, says Walter. "I love this move in at-home workouts because it does not require equipment and is a great move for anyone looking to do more [high-intensity interval training] (HIIT), "she adds.

"It's not just strength and it's not just cardio," says Mansour of this move. "It's two in one."

Make that more like seven in one. The explosive element of this movement tests your speed and power, which are especially important skills in many sports, and because you are jumping up and switching your stance mid-air, you're working your agility, balance, and coordination as well, says Mansour.

Because this move is high-impact, there are a few things to consider before giving it a go.

Before you try jump lunges for yourself (more on that below), it's important to master both walking lunges and jump squats, recommends Mansour. You should be able to comfortably do 8 reps of each with a solid form before attempting jump lunges. (For walking lunges, that means 8 reps on each side, or 16 lunges total.)

Another caveat: Any jumping movement that involves a great deal of strength knee pain, says Walter, as well as anyone. 91 low-back pain, adds Mansour. For a lower-impact alternative, you can do alternating lunges without a jump and add in a weight like a medicine ball or dumbbells to make the move more challenging, suggests Walter. But if you do have any sort of pain, you should always check in with your doctor before starting a new exercise to make sure it's safe for you.

All that said, if you're ready to try jumping lunges, Here's how to do them:

Remi Pyrdol
  • Stand with your feet shoulder-width apart.
  • Step back (about 2 feet) with your left foot, landing on the ball of your left foot and keeping your heel off the floor.
  • Bend both knees to create two 90-degree angles with your legs. Bend your elbows and put your hands on your hips. (In this position, your shoulders should not be above your hips and should not be upright). Your right shin should be perpendicular to the floor and your right knee should be stacked above your right ankle. Your left thigh should be perpendicular to the floor. Your butt and core should be engaged.
  • Push through the heel of your right foot up.
  • As you jump, switch your stance so that your right foot goes back about 2 feet, landing on the ball of your right foot and keeping your heel off the ground. Your left foot is now in front, flat on the floor, facing forward.
  • Bend both knees again to create two 90-degrees angles with your legs. This is 1 rep.
  • Without pausing, pushing through the heel of your left foot and the ball of your right foot to jump up, switching your stance again and sinking down into the lunge.
  • Continue with this sequence, jumping and switching your stance in between each lunge.
  • Do 8 reps.

To get the most out of the move, your jumps should feel controlled and be done continuously, with no stopping between reps.

You want to really stick your landings and maintain a correct body positioning throughout, with your core engaged, back straight, and hips pushed back, says Mansour. It may help to put markers on the floor so you know where to land to keep your feet hip-distance apart and in the right positioning to form 90 degree angles when you lower into the lunge./107

On said landings, your front foot should be making full contact with the ground—not just your tiptoes, says Mansour. Your back foot will be slightly lifted, with your toes and the ball of your foot grounded.

If you are having trouble sticking your landings or otherwise feel wobbly, you can add extra stability into the movement or bar, or gripping TRX bands as you jump, says Mansour. Your torso should stay upright throughout. "Do not lean forward or backward," says Mansour. If you find yours, torso, tilting forward, clasp your hands behind your head to help shift your weight back.

Lastly, the reps should be performed as one continuous movement. Do not pause at the bottom of each lunge. "You do not want to reset and lose your momentum," says Mansour. For this reason, it's OK if your back knee does not bend down as far as it can lunge 113