How are squat jacks different from jumping jacks?

A Jumping Jack stays nearly upright with only a slight knee bend, while a squat jack drops into a deep, wide squat on every rep. That bigger range makes squat jacks harder on the legs and lungs, so most people manage fewer of them.

Do squat jacks build muscle?

They build leg endurance and some quadriceps and glute strength in beginners, but body weight alone soon stops being enough load to keep building muscle. For leg size and strength, pair them with loaded squats and use squat jacks for conditioning.

Is there a low-impact version of squat jacks?

Yes. Step one foot out into the wide squat and back in, alternating sides, or perform a Bodyweight Sumo Squat with an overhead arm reach, which keeps the squat without any landing.

How many squat jacks should I do?

A good starting point is 3 or 4 rounds of 20 to 30 seconds, or 10 to 15 reps, with enough rest to keep every landing controlled. Build up by lengthening the intervals or shortening the rest as your fitness improves.

Should I stand all the way up between reps?

Both versions are common. Standing tall between reps, as shown here, gives a bigger jump and a fuller range, while staying in a half squat and jumping the feet in and out keeps the legs working without a break.

Squat Jack

What Is the Squat Jack?

Squat Jack is a compound exercise that primarily targets the quadriceps and also engages the glutes, calves and inner thighs while driving the heart rate up. It is a beginner-level movement that needs no equipment, and it adds a deep, wide squat to the in-and-out footwork of the Jumping Jack.

Most trainers use squat jacks as a conditioning drill in circuits, HIIT intervals and warm-ups rather than as a strength exercise. Each rep is a jump out into a wide squat and a jump back to standing, so the legs move through a much bigger range than in a regular jumping jack and the heart rate climbs quickly. They are usually programmed for a set number of reps or a short timed interval, such as 20 to 30 seconds with rest between rounds.

The wide stance with the toes turned out puts most of the work into the quadriceps and glutes, while the inner thighs help control the drop into the squat and the calves absorb every landing and drive every take-off. The overhead arm swing adds some shoulder work and helps with rhythm, but it carries no real load. A common variation keeps the hips low and jumps the feet in and out from a half squat without standing up between reps, which keeps the legs working the whole time. The version shown here returns to a tall stance after each rep, so every rep includes a full jump into and out of the squat.

Squat jacks suit anyone who can already perform a controlled Bodyweight Sumo Squat and a minute of jumping jacks without knee or ankle pain. If the impact is too much, the sumo squat on its own trains the same leg pattern, and the Step Jack keeps the jack rhythm with no jumping at all. Once squat jacks feel easy, the Jump Squat asks for a more powerful vertical jump.

Muscles Worked

MuscleActivation

Vastus Lateralis: Primary
Vastus Medialis: Primary
Gastrocnemius (Lateral Head): High
Gastrocnemius (Medial Head): High
Gluteus Maximus: High
Adductor Magnus: Medium
Rectus Femoris: Medium
Soleus: Medium
Deltoid: Low
Rectus Abdominis: Minimal

Instructions

Stand tall with your feet close together and your hands on your hips.
Brace your core and bend the knees slightly to load for the jump.
Jump both feet out wide, turning the toes out, and swing both arms straight overhead.
Land softly through the balls of the feet, let the heels settle and sink into a deep, wide squat with your thighs close to parallel.
Keep your chest up and push the knees out in line with the toes at the bottom.
Drive through the feet to jump back up, bringing the feet together and the hands back to the hips.
Land softly in the tall starting stance with the knees slightly bent.
Repeat for the planned reps or time, keeping every landing quiet and controlled.

Common Mistakes

Knees caving in
Letting the knees fall inward when landing in the wide squat strains the knees, so keep them pushed out in line with the toes.
Landing stiff and loud
Landing with straight legs or slapping down flat-footed sends the impact into the joints instead of the muscles.
Heels lifting in the squat
Rising onto the toes at the bottom shifts the load into the knees and costs balance, so let the heels settle before the next jump.
Collapsing the chest
Folding forward and rounding the back in the squat turns a leg drill into a strain on the lower back.
Shallow, bouncy reps
Barely bending the knees as the pace rises turns the exercise back into a plain jumping jack and loses most of the leg work.
Chasing speed over control
Rushing the reps until the landings get sloppy defeats the purpose, so slow down as soon as form starts to slip.

Injuries

Squat Jack is a low risk exercise when performed with proper technique. The knees and ankles take the most stress, because every rep ends in a landing that drops straight into a deep, wide squat. Stiff-legged or flat-footed landings, knees that collapse inward as the feet hit the floor, and heels that lift in the bottom of the squat are the usual sources of knee and ankle discomfort.

Land softly through the balls of the feet and let the heels settle, then bend the hips and knees to absorb the landing quietly. Keep the knees pointing the same way as the toes, the chest up and the trunk braced. Only squat as deep as you can while keeping the heels down and the back flat, and slow the pace down when fatigue starts to break your form, since sloppy landings late in an interval are where most problems start.

If jumping is uncomfortable or not yet appropriate, perform a Bodyweight Sumo Squat with the arm raise, or swap to the Step Jack for the same rhythm without impact. A softer floor or a gym mat also takes some sting out of the landings. To progress, increase the speed or interval length before adding a bigger jump such as the Jump Squat.

Stop if you feel sharp pain in the knees, ankles, shins or hips, or if dizziness or unusual breathlessness sets in. Anyone with a recent lower-limb injury, joint replacement or a condition that limits high-intensity exercise should get clearance before adding jumping drills.

Overview

Primary Focus: Cardio and quads
Equipment: Body weight
Modality: Cardio
Difficulty: Beginner

Alternative Exercises

Frequently Asked Questions

Q: How are squat jacks different from jumping jacks?: A Jumping Jack stays nearly upright with only a slight knee bend, while a squat jack drops into a deep, wide squat on every rep. That bigger range makes squat jacks harder on the legs and lungs, so most people manage fewer of them.
Q: Do squat jacks build muscle?: They build leg endurance and some quadriceps and glute strength in beginners, but body weight alone soon stops being enough load to keep building muscle. For leg size and strength, pair them with loaded squats and use squat jacks for conditioning.
Q: Is there a low-impact version of squat jacks?: Yes. Step one foot out into the wide squat and back in, alternating sides, or perform a Bodyweight Sumo Squat with an overhead arm reach, which keeps the squat without any landing.
Q: How many squat jacks should I do?: A good starting point is 3 or 4 rounds of 20 to 30 seconds, or 10 to 15 reps, with enough rest to keep every landing controlled. Build up by lengthening the intervals or shortening the rest as your fitness improves.
Q: Should I stand all the way up between reps?: Both versions are common. Standing tall between reps, as shown here, gives a bigger jump and a fuller range, while staying in a half squat and jumping the feet in and out keeps the legs working without a break.