The Exercise That Never Built Complete Legs

Every training source you've consumed delivers the same ranking. Squats sit at the top. Leg press below. Extensions somewhere beneath that. The hierarchy is so deeply embedded in gym culture that skipping squats feels like cheating — even when your knees ache, even when your home gym has no rack, even when you'd honestly rather do anything else on leg day.

There's a question hiding inside that ranking that almost nobody thinks to ask. Not whether squats are hard or functional or important for strength. Whether squats actually grow every muscle in your legs.

Can you build legs without squats — and what do squats actually grow?

When researchers measured what squats produce in each lower-body muscle group, the hierarchy started to collapse. The quad's vasti respond well. That part of the reputation is earned.

The hamstrings tell a different story. A narrative review of the squat-training studies that tracked the hamstrings found the same result in all of them: near-zero growth. Six studies. Subjects — most of them young men new to lifting — squatting for weeks or months. Quad growth ranging from respectable to impressive. Hamstring growth ranging from 0% to 3%.

The calves are likely no better off. Your ankle joint absorbs substantially less force during a squat than your hips and knees produce. The calf muscles barely participate. Whether squats grow the calves at all has barely been tested: a 2023 meta-analysis knew of no study on what compound lifts do for calf growth, though its authors judged such lifts likely suboptimal there.

The reason isn't bad form or insufficient depth. Your hamstrings cross both the hip and the knee. During a squat, they stretch at one end while shortening at the other. That tug-of-war reduces their capacity to extend the hip, and the review's authors posit null or reduced hamstring activation in the squat, especially relative to the quads.

So the exercise at the top of the ranking has a blind spot at the hamstrings, and the review expects one at the calves. Which raises the question the lifter carrying squat-guilt actually needs answered: do the alternatives work?

Thirteen controlled studies compared machines with free weights, over a thousand people in all. Five of them measured muscle growth, and found no difference between the two. In those five, machine programmes, three of them using the leg press, showed no difference in growth from free-weight programmes that mostly used the barbell squat.

The evidence goes further than that. Leg extensions grew the quad head at the front of your thigh — the one squats struggle with — at nearly twice the rate of leg press. Leg press grew the outer quad at almost three times the rate of extensions. Both grew both regions, but each grew one region more. Mixing compound and isolation work is what the study's authors suggest for the quad.

The authors put it carefully: it would seem that a mix of multi-joint and single-joint exercise is needed to fully develop the quad. That is a conclusion drawn from legs that each trained one exercise, not a tested combination.

The hierarchy's blind spots don't stop at squats. Deadlifts sit on the same pedestal — and the evidence underneath looks identical.

The lifter who arrived asking whether it's okay to skip squats now faces a sharper question. Not whether squats are optional — but what combination of exercises covers every muscle in the lower body. The hierarchy's top-ranked exercise has blind spots of its own — and the training the reader already does may be closer to the answer than they realized.