How to do the Plank Jack
- Forearm plank, elbows under shoulders, feet together.
- Jump your feet out wide, then back together.
- Keep your hips level and your upper body still.
- Keep your stomach tight at a steady pace.
Full technique — 7 steps
- Set up in a forearm plank with elbows under your shoulders and forearms flat on the floor.
- Extend your legs behind you with feet together and your weight on your toes.
- Tighten your stomach, squeeze your glutes, and keep your ribs in line with your pelvis.
- Jump both feet out to the sides, a little wider than your shoulders.
- Jump your feet back together to return to the start position.
- Keep your hips level with your shoulders and your upper body still throughout.
- Repeat at a steady pace without letting your hips bounce or rise.
Common mistakes
- Hips sagging below shoulders
- Piking the hips up each jump
- Letting the lower back arch
- Shifting weight side to side
- Shrugging shoulders toward ears
Form cues
- Keep ribs down
- Squeeze glutes hard
- Keep hips mostly still
- Land lightly on toes
Where to start and where to go next
Same muscles, same movement. Too hard for now — step down; once it gets easy — step up.
- This exercise Plank Jack
- Harder Pike Jack
Quick answers
What muscles does the Plank Jack work?
Primary: Abs 8/10, Obliques 7/10. Also works: Lower back 4/10.
How many sets and reps of the Plank Jack?
Strength: 2–3 sets of 10–15 reps, rest 1 min, 3–4 reps in reserve. Muscle growth: 2–3 sets of 15–20 reps, rest 45 s, 3 reps in reserve. Endurance: 2–4 sets of 20–40 reps, rest 30 s, 3 reps in reserve.
What is a harder version of the Plank Jack?
Pike Jack (55% of bodyweight).
