Jumping jacks: how to do them, what the studies measured, and a no-jump swap

A jumping jack is a jump on the spot: your feet go from together to wide and back while your arms swing from your sides to overhead and back. A low-impact list will tell you to swap it out.

This page covers the steps, the faults, what the few studies that include the move measured, why it isn't low impact, a no-jump swap, and how many to do. Other jumping moves have their own pages: burpees, mountain climbers and the jump rope workout.

How to do a jumping jack

1. Stand tall with your feet together, your arms by your sides and your knees soft.
2. Jump your feet out to a little wider than your shoulders while your arms swing out and up, hands reaching overhead.
3. Land softly on the balls of your feet with your knees slightly bent, just as your hands reach the top.
4. Jump your feet back together while your arms come down to your sides. That's one rep.
5. Keep a steady rhythm you can hold for the whole round, and breathe.

These are coaching cues, not study findings. The one that matters most: land quietly.

The common faults, and a fix for each

• Landing on stiff, straight knees. Land with your knees slightly bent every rep.
• Feet too wide. A little wider than your shoulders is enough; wider makes each landing harder to control.
• Arms and feet out of time. Both reach the top together, so the arms swing with the jump, not after it.
• Speeding up as you tire. When the rhythm breaks or the landings get loud, rest.

What the studies measured

Jumping jacks appear in research as one move inside a mixed circuit. No study turned up in a PubMed search for this page that trained people on jumping jacks alone, measured muscle activity in them, or compared them with jump rope. What does exist:

• The energy cost of a short bout. In 10 healthy young adults who did seven body-weight exercises for 30 seconds and for 45 seconds, total energy expenditure for jumping jacks was 23.1 kilocalories a minute in the 30-second trial and 22.8 in the 45-second one. For comparison, the plank was 11.3 and 12.6, the squat 19.9 and 23.2, and burpees 32.2 and 40.7.¹ These are rates over a short burst, not what a longer session adds up to.
• Four weeks of 20-second rounds. In 22 recreationally active women, the 7 who trained four days a week with one set of eight 20-second rounds of a single exercise (burpees, jumping jacks, mountain climbers or squat thrusts), with 10 seconds of rest between rounds, raised their aerobic fitness (peak oxygen uptake) by about 8%, against about 7% for the 7 who did 30 minutes on a treadmill. The interval group's muscular endurance improved too.²
• Six weeks against running. In 25 active, healthy adults, 14 did 20 rounds of 30 seconds all-out with 30 seconds of passive recovery, using jumping jacks, mountain climbers, burpees and squat jumps, three times a week; 11 ran continuously for 20 minutes at 80% of their maximum heart rate. On the functional tests the interval group did better only on push-ups, and muscle thickness in the arms and legs didn't change significantly in either group.³

In both training trials the jacks were one move in a mix, so neither can say what jacks alone do. They show that short bodyweight circuits have been used as interval training; they say little about the jack itself.

Are jumping jacks low impact?

No. The low impact workout defines low impact as no moment with both feet off the ground, and a jumping jack has two in every rep.

The no-jump swap is the step jack:

1. Start with your feet together and your arms by your sides.
2. Step your right foot out to the side while your arms sweep overhead.
3. Step it back as your arms come down, then do the left side. One step out on each side is one rep.

One foot is always on the ground, so it passes the low-impact test. No study compared a step jack with a jumping jack; it is the swap the low impact page lists.

How many, and how hard

The interval studies above used rounds of 20 or 30 seconds with 10 to 30 seconds of rest. A practical way to start, not taken from a study: three rounds of 30 seconds of jacks with 30 seconds of rest, adding a round each week up to eight. As a warm-up, one or two easy minutes is plenty.

Judge the effort rather than the count. The World Health Organization describes moderate activity as usually a 5 or 6 on a 0-to-10 scale of effort, and vigorous activity as a 7 or 8.⁴ Its guideline for adults is at least 150 to 300 minutes of moderate or at least 75 to 150 minutes of vigorous aerobic activity a week, or an equivalent mix, and some activity is better than none.⁴ Jacks that feel like a 5 or 6 to you count as moderate on that scale.

Where it fits in your week

• As a warm-up: one or two easy minutes before a session, ahead of the moves in the lifting warm-up.
• As a finisher: three to five rounds after your lifting, then the core block in the core workout if you do one.
• In a bodyweight session: as the cardio round beside the squat, push and core moves in the bodyweight workout.

Common questions

What muscles do jumping jacks work?

No study measured muscle activity in a jumping jack, so this page can't rank the muscles. The move asks your legs to push off and land and your shoulders to swing your arms overhead.

Jumping jacks or jump rope?

No study that compared the two turned up in a PubMed search for this page. The jump rope workout covers the rope on its own terms.

What if something hurts?

If you have pain, an injury or a medical condition, a doctor or a physical therapist should set the limits before you train; this page is general guidance for healthy adults.

If you'd rather have the week planned

A move on a page doesn't know your days. Coaching is the version where your workouts live in Trainerize, built around the days and the equipment you actually have, and a weekly call looks at how the week went and sets the next one. Coaching for beginners explains how the first weeks work, and apply is the first step. Otherwise: tomorrow, do three rounds of 30 seconds, jumping or stepping, and write down how the last round felt on a scale of 0 to 10.