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?
Squats effectively grow the largest quad muscles and glutes but produce near-zero hamstring growth across every study that tracked it, and the calves receive too little stimulus to grow at all. Machines produce equivalent muscle growth to free weights. Building complete legs requires combining different exercise types — the approach most squat-skipping lifters already use.
— Nunes et al. 2023 · Strength & Conditioning Journal · Narrative review of all squat hypertrophy studies; Haugen et al. 2023 · Meta-analysis · 13 studies, n=1,090
When researchers measured what squats produce in each lower-body muscle group, the hierarchy started to collapse. Your two largest quad heads respond well. That part of the reputation is earned.
The hamstrings tell a different story. A review covering every longitudinal study that tracked hamstring growth during squat training 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 exercise that gym culture crowned king of leg development was never growing half the leg.
The calves don't fare better. Your ankle joint absorbs substantially less force during a squat than your hips and knees produce. The calf muscles barely participate. No study has found enough calf growth from squats to measure — not because research is sparse, but because there's nothing to find.
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 activation to nearly nothing compared to the quads. The physics of the movement cannot load them.
So the exercise at the top of the ranking has a structural blind spot spanning three muscle groups. Which raises the question the lifter carrying squat-guilt actually needs answered: do the alternatives work?
Thirteen controlled studies tested this directly — over a thousand people training with either machines or free weights. The finding: equivalent muscle growth from both. The leg press you load every session, the extensions you treat as an afterthought — they match the barbell squat for building muscle.
The evidence goes further than equivalence. 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. No single exercise covered the entire quad. Mixing compound and isolation work across different angles was always the structurally superior strategy.
The data points in one direction: both multi-joint and single-joint exercises are required for full quad development. Neither type alone is sufficient. The synergistic effect of combining them reaches territory no single movement can.
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 was always the one with the largest blind spots — and the training the reader already does may be closer to the answer than they realized.