You’re at the gym. You see someone jumping like a frog, feet snapping together and then wider than their shoulders, over and over. They look exhausted. Honestly, they probably are. That's the in and out squat. It looks simple, almost like a playground game, but it’s actually one of the most misused movements in the functional fitness world. Most people treat it like a mindless cardio filler. They’re wrong.
When you do in and out squats correctly, you aren’t just burning calories. You’re hitting the adductors, the gluteus medius, and building explosive power. If you do them wrong? You’re just begging for a case of "runner’s knee" or an annoyed lower back.
Why In and Out Squats Are More Than Just "Jumping"
Most trainers throw these into a HIIT circuit because they spike the heart rate. Fast. But the real magic is the lateral transition. Think about it. Most of our lives are lived in a straight line. We walk forward. We sit down. We stand up. We rarely challenge the muscles that stabilize our hips from the side.
The in and out squat forces your body to manage center-of-gravity shifts at high speed. It’s a plyometric move. According to the Journal of Strength and Conditioning Research, plyometric training improves neural adaptations, meaning your brain gets better at telling your muscles to fire quickly. It’s not just about the sweat. It's about the connection between your mind and your quads.
You’ve probably seen the "narrow" squat. It hits the outer quad (lateralis). Then you’ve got the wide "sumo" style. That kills the inner thighs. In and out squats basically force those two worlds to collide in a single repetition. It's efficient.
The Form Breakdown (And How You're Probably Messing It Up)
Stop thinking about the jump. Start thinking about the landing.
Start with your feet under your hips. Drop into a shallow squat. Now, explode upward just enough to clear the floor. Your feet should land wider than your shoulders. Your toes should point slightly out. As soon as you hit the ground, sink into that deep squat. Keep your chest up. If you look at the floor, your spine rounds, and suddenly you’re putting 400% more stress on your lumbar discs than you need to.
The Narrow Phase
When you hop back "in," your feet shouldn't touch. Leave a few inches. This keeps the tension on the glutes and prevents you from "resting" at the top. If your knees knock together—which happens a lot when people get tired—you’re in trouble. That’s called knee valgus. It’s the primary cause of ACL strains in jump-based exercises.
The Wide Phase
Don't just go wide for the sake of it. Go as wide as your hip mobility allows. If your heels lift off the ground when you go wide, you’ve gone too far or your calves are too tight. Keep those heels glued down. Impact should be absorbed by the midfoot and heel, never just the balls of your feet.
Real Talk: Does This Actually Build Muscle?
Let’s be real. If you want huge legs, you need a barbell. You need heavy back squats. But in and out squats serve a different master: hypertrophy through metabolic stress.
By staying low—essentially staying in a "crouched" position throughout the entire set—you create a state of hypoxia in the muscle. Blood can’t leave the muscle as fast as it’s entering. This creates that "pump" feeling. For an athlete, this is gold. It builds endurance in the type II muscle fibers.
I’ve seen people use these as a "finisher" after a heavy leg day. Imagine finishing four sets of heavy five-rep squats and then immediately doing 60 seconds of in and out squats. It’s brutal. It’s effective. It forces the body to adapt to high-acidosis environments.
The Knee Pain Myth
"Jumping ruins your knees."
I hear this at the clinic all the time. It’s a half-truth. Impact is actually good for bone density and tendon stiffness. The problem isn't the in and out squat; it's the lack of deceleration. If you land like a ton of bricks, yeah, your knees will hate you. You need to land like a cat. Silent. If I can hear your feet slamming the gym floor from across the room, you’re doing it wrong.
A study by the American Council on Exercise (ACE) found that proper landing mechanics—specifically landing through the forefoot and immediately rolling to the heel while flexing the hip—reduces ground reaction force significantly. Use your muscles as shock absorbers. Don't let your joints take the hit.
Variations That Don't Suck
Maybe you can't jump. Maybe you live on the third floor of an apartment with paper-thin floors. You can still reap the benefits.
- The Stepping In and Out Squat: Instead of a jump, stay in a low "ready" position and step out-out-in-in. It sounds like a dance move. It feels like fire in the quads. You’re maintaining a constant isometric hold while moving your limbs.
- The Weighted Goblet Version: Hold a kettlebell at your chest. It changes your center of mass. This actually makes it easier for some people to stay upright, though it makes the heart work twice as hard.
- The Banded Burner: Put a mini-band around your calves. Now, try to do the in and out squat. The band wants to snap your knees inward. Your gluteus medius has to fight like hell to keep them out. This is arguably the best way to pre-hab your knees while getting a workout in.
Common Misconceptions and Traps
People think these are "cardio." They aren't. Not really. Burpees are cardio. In and out squats are a strength-endurance hybrid. If you’re doing them so fast that your form looks like a glitching video game, you’ve lost the plot.
Another mistake? The "Hunchback." People get tired and let their shoulders roll forward. They start reaching for the floor with their hands. Your hands don't need to touch the floor. Your butt does. Keep your eyes on the horizon.
Also, don't do these every day. Plyometrics require CNS (Central Nervous System) recovery. Treat them with the same respect you'd give a heavy deadlift session. Twice a week is plenty for most people.
Creating a Routine That Works
If you're looking to actually see results, don't just "do some" at the end of a workout. Structure it.
Try a Tabata style: 20 seconds of maximum effort in and out squats, followed by 10 seconds of rest. Repeat that eight times. It’s only four minutes, but by the end, your legs will feel like lead.
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Or, if you’re a runner, use them as a primer. Doing 15-20 reps before a run "wakes up" the lateral stabilizers that often go dormant during long, repetitive forward strides. It can actually help prevent IT band syndrome.
How to Scale for Real Progress
Progressive overload isn't just about adding weight. With in and out squats, you can progress by:
- Increasing the depth of the wide squat.
- Reducing the "ground contact time" (how fast you can get back into the air).
- Adding a "pulse" at the bottom of the wide phase.
Basically, the goal is to increase the time under tension.
Actionable Steps for Your Next Workout
Don't just read about it. Try it. But do it with a plan.
Step 1: The Mobility Check. Spend two minutes in a deep "prayer" squat. Move side to side. If your hips feel like rusty hinges, do some 90/90 hip flips first.
Step 2: The Warm-up. Do 10 slow air squats. Then 10 lateral lunges. You need the blood flowing to the inner thighs before you start snapping them in and out.
Step 3: The Set. Set a timer for 45 seconds. Focus on the landing. Be silent. Keep your chest up. If you feel your form slipping at 30 seconds, stop. Low-quality reps are worse than no reps.
Step 4: Recovery. Stretch your adductors afterward. Those muscles on the inside of your thigh are going to be tight. Use a foam roller if you have one.
In and out squats are a tool. They are a bridge between pure strength and pure athleticism. Stop treating them like an afterthought. Control the descent, explode through the floor, and keep your core braced. Your legs—and your heart rate—will thank you (evently).