Plank jacks are like jumping jacks done in a plank. You hold a high plank on straight arms and hop your feet out wide, then back together, over and over, while your trunk stays still. Your stomach and shoulders hold the plank and your hips and legs do the jumping. Because of the hopping, it raises your heart rate as well as working your core.

How to do the plank jacks

Get into a high plank with straight arms, your hands flat on the mat below your shoulders and your feet together, weight on your toes.
Tighten your stomach so your body forms one line from your head to your heels.
Hop both feet out to the sides, landing a little wider than your shoulders.
Hop them straight back together. Land softly and keep your hips at the same height the whole time, so they do not bounce or twist.
Carry on at a steady rhythm with your hands still, and keep breathing.

What you should feel

Your stomach, shoulders and arms hold the plank while your outer and inner thighs move your legs. You will get out of breath quickly, and your pulse climbs with it.

Common mistakes

Hips sagging toward the floor or bouncing up and down with each hop.
Shoulders drifting forward past the hands.
Landing heavily instead of softly on the toes.
Jumping the feet so wide that the hips twist.

How often

Many programs start with 2 to 3 rounds of 15 to 30 seconds, or 8 to 16 jacks, with rest in between. Your physio will adjust this.

Stop and check with your physio if

Chest pain or pressure, dizziness or feeling faint, a racing or irregular heartbeat, or being far more out of breath than the effort should cause.
Wrist, shoulder or lower back pain that gets sharper as you go.
Leaking urine or a heavy, dragging feeling in the pelvis.
A sudden pop or snap at the back of your ankle or heel, a feeling that someone kicked you there, or sudden pain there after which you cannot push off or rise onto your toes on that leg. Stop, take the weight off that leg carefully and go to an urgent care center or emergency department the same day, even if you can still walk, as this can be a torn Achilles tendon.

From the clinic

Learn it without the hop first. Step one foot out to the side and back, then the other, keeping your hips still, and add the small jump only once that feels steady. If your wrists or shoulders tire, raise your upper body by placing your hands on a firm step or bench. A still plank and mountain climbers use the same position with different leg work.

Each hop puts load through the pelvic floor and the bones. If jumping, coughing or sneezing makes you leak urine, or you have osteoporosis, stay with the stepping version unless your physio has cleared you to jump.

If you have had a hip or knee replacement, get the go-ahead from your surgeon before you try plank jacks. Many surgeons advise against jumping and hopping after a joint replacement for good, not just for the first months, because each landing sends high impact through the new joint. If you are pregnant or had a baby recently, check with your physio or midwife first. After shoulder or wrist surgery, or a shoulder dislocation, ask your physio when it is safe to take your weight on your hands.

With high blood pressure or a heart problem, get your doctor's advice before fast work like this. If chest pain, pressure or tightness does not ease quickly when you rest, spreads to your arm, neck, jaw, stomach or back, or comes with sweating, feeling sick, feeling light-headed or being short of breath, call emergency services straight away, as this can be a heart attack. If it eases quickly and none of these happen, get medical advice the same day, and do not exercise again until you have been checked. If you faint while exercising, call emergency services, even if you feel fine again quickly.

Written and checked by the PocketPhysio editorial team. Last updated 2026-09-28.

This page is general education, not a diagnosis or a personal treatment plan. If you have pain, an injury or a health condition, see a physiotherapist or doctor before starting new exercises.

Plank jacks