Can You Really Squat?

The squat is called the king of exercises. Rightly so – but partly for different reasons than you hear in the gym. What research actually says about depth, knees, hormones, sprint performance and bones.

Sit down, stand up. Every person does this dozens of times a day – from the sofa, from the toilet, out of the car. The squat is nothing more than this everyday movement, just with load, with a plan and with clean technique. And that is exactly where its value lies.

Still, hardly any exercise is surrounded by as many myths. "Deep squats wreck your knees." "Your knees must never pass your toes." "Squats boost your testosterone." Time for a fact check.

Why the Squat Does So Much

A free barbell squat is not a leg exercise. It is a full-body task:

• —Hip and knee extensors – mainly quads, glutes and adductors – move the load.
• —Trunk and spinal erectors keep the torso stable and transfer the force.
• —The nervous system has to coordinate dozens of muscles with precise timing – under a load that is often heavier than your own body weight.

This combination of high mechanical tension, large muscle mass and coordinative demand is why sports science treats the squat as the fundamental exercise. It doesn't train individual muscles, it trains a movement pattern.

Myth 1: "Deep Is Bad for Your Knees"

If anything, the opposite is true. In 2013, sports scientists Hagen Hartmann, Klaus Wirth and colleagues reviewed the available literature on knee and spine loading. Their conclusion: with clean technique, there is no evidence that deep squats put passive structures like ligaments, menisci or cartilage at greater risk than half squats.

One reason is the so-called wrap effect: in the deep position, the quadriceps tendon lies against the thigh bone over a large area, and thigh and calf touch each other. The force is spread over a larger surface. The authors even point to a different risk: people doing half or quarter squats often load much more weight – and can end up stressing knees and spine more than with the deep variant and less load.

One caveat: if you already have knee problems, work out your depth with a coach or physiotherapist. For healthy knees: depth isn't a risk, it's training.

Myth 2: "Your Knees Must Not Pass Your Toes"

This one is stubborn too. A study by Andrew Fry and colleagues (2003) shows what happens when you artificially keep the knee behind the toes: knee load drops slightly – but hip torque rises massively and the torso has to lean further forward. The load simply moves into the lower back.

How far your knee travels forward depends on your proportions – thigh length, ankle mobility, stance. What matters is that your foot stays planted and your knee tracks in the direction of your toes. Not where it sits relative to the tip of your shoe.

Depth Pays Off for Muscle Growth Too

In 2019, the Japanese research group around Keitaro Kubo had two groups squat for ten weeks: one to a 90-degree knee angle, one to 140 degrees – in other words, deep. The result: the front of the thigh grew similarly in both groups. But glutes and adductors grew considerably more in the deep group.

The reason: these muscles are only really stretched and loaded in the deep position. Stop halfway and you give away a big part of the training stimulus.

Myth 3: "Squats Boost Your Hormones"

You read this a lot: big compound lifts like the squat supposedly create a "disproportionate anabolic stimulus" because they briefly raise testosterone and growth hormone. The short-term rise is real – but it doesn't seem to matter for muscle growth.

A study by Daniel West and Stuart Phillips (2010) showed this elegantly: participants trained one arm alone and the other arm together with heavy leg training that clearly raised hormone levels. Both arms got equally strong and equally big. Later reviews confirm the picture.

Meaning: the squat is great for the muscles it trains. Your arms won't grow along with them.

The Transfer: Strong Squatters Jump and Sprint Better

The evidence is really strong when it comes to carry-over to athletic performance:

• —Back in 2004, Norwegian researchers around Ulrik Wisløff found a very close link between maximal squat strength, sprint time and jump height in professional footballers.
• —A meta-analysis by Laurent Seitz and colleagues (2014) shows: increase your lower-body strength and, on average, you get faster in the sprint – and the effect is substantial.

The same goes for everyday life: stairs, getting up, carrying heavy groceries, lifting your kid. The squat trains exactly the strength you need for that.

Bonus: Squats Strengthen Your Bones

Bones – like muscles and tendons – respond to load. The Australian LIFTMOR trial (Watson et al., 2018) had postmenopausal women with low bone density train heavy under supervision for eight months – including squats and deadlifts. Result: bone density at the lumbar spine and femoral neck increased instead of declining as usual, and physical function improved. Serious injuries: none.

So heavy squats aren't just for young athletes. With proper coaching, older people in particular benefit.

So: Can You Really Squat?

The question is meant seriously. The benefit stands or falls with execution. A few checkpoints:

• —1. Planted feet: Whole foot on the floor, weight over mid-foot.
• —2. Knees follow the toes: No caving in, especially on the way up.
• —3. Brace before you move: Breathe in, lock your trunk, then go down.
• —4. Depth by control: As deep as you can with a stable back – for most people at least until the hip crease is below knee height.
• —5. Bar over mid-foot: The bar travels as vertically as possible.

Sounds simple, but it isn't always. Ankle and hip mobility, trunk stability and body awareness decide how good the movement looks. This is exactly where a critical outside eye pays off.

Key Takeaways

• —The squat trains a movement pattern, not just muscles – and you need that pattern in sport and everyday life.
• —With clean technique, deep squats are not harmful for healthy knees. Deep does more for glutes and adductors.
• —Knees past the toes are normal. Preventing it shifts the load into hips and back.
• —The short-term hormone spike is not a reason for muscle growth all over your body.
• —More squat strength means measurably better sprint and jump performance – and stronger bones.

Sources (selection)

• —Hartmann H., Wirth K., Klusemann M. (2013): Analysis of the load on the knee joint and vertebral column with changes in squatting depth and weight load. Sports Medicine, 43, 993–1008.
• —Fry A. C. et al. (2003): Effect of knee position on hip and knee torques during the barbell squat. Journal of Strength and Conditioning Research, 17(4).
• —Kubo K. et al. (2019): Effects of squat training with different depths on lower limb muscle volumes. European Journal of Applied Physiology, 119.
• —West D. W. et al. (2010): Elevations in ostensibly anabolic hormones with resistance exercise enhance neither training-induced muscle hypertrophy nor strength of the elbow flexors. Journal of Applied Physiology, 108.
• —Wisløff U. et al. (2004): Strong correlation of maximal squat strength with sprint performance and vertical jump height in elite soccer players. British Journal of Sports Medicine, 38.
• —Seitz L. B. et al. (2014): Increases in lower-body strength transfer positively to sprint performance: a systematic review with meta-analysis. Sports Medicine, 44.
• —Watson S. L. et al. (2018): High-intensity resistance and impact training improves bone mineral density and physical function in postmenopausal women with osteopenia and osteoporosis: the LIFTMOR randomized controlled trial. Journal of Bone and Mineral Research, 33(2).