Plank Jack

Body Part: Waist

Muscle: Glutes

Equipment: Body Weight

Plank Jack is a bodyweight floor exercise performed from a high plank while the feet jump out and back together, like a jumping jack done without standing up. It trains the glutes, core, and shoulder girdle to stay organized while the legs move quickly underneath the torso. The real challenge is not the jump itself; it is keeping the trunk from sagging, twisting, or bouncing as the feet travel in and out.

The setup matters because the hands, shoulders, pelvis, and feet have to share the load. Start in a straight-arm plank with the hands under or slightly ahead of the shoulders, fingers spread, and the body in one long line from head to heels. Keep the ribs tucked, glutes lightly engaged, and neck neutral so the lower back does not take over when the feet separate.

Each rep should be sharp but controlled. Jump both feet out wider than hip width, then jump them back together without letting the hips rise high or drop low. Land softly on the balls of the feet and keep pressure through the palms so the shoulders stay stacked and stable. Breathing should stay steady, with a short exhale as the feet move and an inhale as you reset the plank.

Use Plank Jack when you want a bodyweight core drill that also raises heart rate, or as a warmup, conditioning finisher, or athletic accessory movement. It can be scaled by stepping the feet out and in instead of jumping, which is useful for beginners or anyone who needs less impact. If the wrists, shoulders, or low back lose position, shorten the set or slow the pace rather than chasing speed.

Instructions

• Place both hands on the floor under or slightly in front of your shoulders and extend your legs into a high plank.
• Spread your fingers, lock in a straight line from head to heels, and keep your gaze a few inches ahead of your hands.
• Bring your feet together behind you with your weight centered between your palms and the balls of your feet.
• Brace your midsection, lightly squeeze your glutes, and keep your ribs from flaring.
• Jump both feet out to a wider-than-hip stance while keeping your shoulders steady over your hands.
• Jump the feet back together under your hips without letting your lower back dip or your hips pike up.
• Land softly and keep the movement quick but quiet, using the core to stop the torso from wobbling.
• Keep breathing through every rep and maintain the plank position until the set is complete.

Tips & Tricks

• Think about pushing the floor away the whole time; that keeps the shoulders active and the chest from collapsing between jumps.
• If your hips bounce up and down, slow the pace and make the feet travel a shorter distance until the torso stays level.
• Keep the feet moving under control rather than slamming them wide, especially on hard floors where noisy landings usually mean lost tension.
• A slightly wider hand position can make the plank more stable if your shoulders feel crowded at shoulder-width setup.
• Do not let the knees bend into a tucked pike during the jump; the goal is to keep the legs long and the trunk steady.
• Exhale as the feet jump out or back together so the core stays braced without holding your breath for the whole set.
• For a lower-impact version, step one foot out and in at a time instead of jumping both feet together.
• Stop the set when your wrists, shoulders, or lower back start taking over, because form breakdown happens quickly with this exercise.

Frequently Asked Questions

What muscle does Plank Jack target most?

The glutes are the primary target muscle group, with the core and shoulders working hard to keep the plank stable while the feet jump.

Is Plank Jack more of a core exercise or a conditioning exercise?

It does both. The plank position challenges the core, while the repeated in-and-out jumps raise the heart rate and add a conditioning effect.

How should my hands and shoulders be set up?

Place your hands under or slightly ahead of your shoulders and keep pressure evenly spread through the palms. That helps the shoulders stay stacked while the feet move.

Should my hips move up and down as my feet jump?

No. The torso should stay as level as possible, with only a small amount of natural movement from the legs and feet.

Can beginners do this exercise?

Yes, but the step-out version is usually a better starting point. Stepping the feet apart and back in reduces impact and makes it easier to control the plank.

What is the biggest form mistake?

The most common problem is letting the lower back sag or the hips rise too high when the feet jump apart.

How can I make Plank Jack easier?

Slow the pace and step one foot out at a time. You can also shorten the range of the leg travel until your torso stays steady.

How can I make Plank Jack harder?

Increase the speed only if the trunk stays quiet, or add more total reps and longer sets while keeping the same clean plank position.