3 sets of squats is enough for strength — 5 sets wins on size, per Schoenfeld's 2019 RCT

The answer is 3 — unless you're chasing size

3 working sets of squats per session is enough to build real strength. That's not a beginner shortcut — that's what a 2019 RCT of 34 resistance-trained men found.

Schoenfeld and colleagues split trained lifters into three groups: 1 set, 3 sets, or 5 sets per exercise per session for 8 weeks. All three groups got significantly stronger on the squat. No significant difference between them (Schoenfeld et al., 2019).

So if your goal is to squat more weight, 3 sets gets you there. You don't need 5 to move the strength needle.

But here's the catch: size is a different story.

All three groups got significantly stronger — with no significant difference between 1, 3, and 5 sets.

— Schoenfeld et al. (2019). Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men. Med Sci Sports Exerc.

For muscle size, 5 sets pulls ahead

When the same study looked at quad muscle thickness — measured with ultrasound at the mid-thigh and lateral thigh — the high-volume group (5 sets) showed significantly greater growth than the lower-volume groups (Schoenfeld et al., 2019).

That gap matters if hypertrophy — building bigger legs — is your primary goal. Three sets keeps your quads growing, but 5 sets pushes the ceiling higher.

A separate RCT confirmed this dose-response pattern. Brigatto et al. (2022) compared 16, 24, and 32 weekly sets per muscle group over 8 weeks in trained men. All volumes increased vastus lateralis thickness — the big quad muscle on the outside of your thigh — but the magnitude of increase tracked with volume. More sets, more size.

The practical takeaway: if you're short on time, 3 sets is not a compromise. It's a legitimate target. If leg size is the priority and you have the recovery, pushing toward 5 sets per session is backed by the data.

What's the absolute minimum you can do and still make progress?

If life gets in the way — travel, a packed week, a short session — how low can you go?

A 2020 Sports Med meta-analysis — a review that pools results across multiple studies — looked specifically at the minimum training dose needed to increase 1RM strength (the maximum you can lift for one rep) in trained individuals on the squat, bench press, and deadlift. The finding: even a single heavy set per session, done consistently, can maintain and increase squat strength in trained lifters (Androulakis-Korakakis et al., 2020).

That's not a license to do one lazy set and call it a day. The key word is heavy — close to your working intensity, with real effort. But it does tell you that on a compressed week, 1–2 hard sets of squats keeps the adaptation alive.

For most training weeks, though, you want that 3-set baseline.

Even a single heavy set per session can maintain and increase squat strength in trained lifters.

— Androulakis-Korakakis et al. (2020). The Minimum Effective Training Dose Required to Increase 1RM Strength. Sports Med.

Weekly volume matters more than per-session sets

Here's the framing shift that changes how you programme squats: the total number of sets you do per week counts more than how many you do in a single session.

A 2021 narrative review — a paper that synthesises research to draw practical conclusions — in Sports Med put it plainly: weekly training volume is more important than training frequency. Their minimum recommendation for hypertrophy is 4 weekly sets per muscle group, using a 6–15 rep loading range (Iversen et al., 2021).

That means if you squat twice a week and do 3 sets each session, you're at 6 weekly sets — already above the minimum threshold. If you squat once a week and do 5 sets, you're at 5 weekly sets — still in the productive zone.

Both approaches work. The distribution is flexible; the weekly total is what you protect.

For context on how this fits into your overall leg training, how many sets per muscle group per week breaks down the weekly volume numbers for every muscle group — including quads.

How hard you push each set changes the equation

Sets aren't equal. A lazy set of 5 reps with 40% of your max isn't the same stimulus as a hard set of 8 taken close to failure.

A 2020 RCT using the full squat — a study where researchers controlled exactly how much speed loss was allowed per set — found that groups doing higher-effort sets (allowing 20–40% velocity loss, meaning they pushed harder and closer to their limit) showed significant quad muscle growth, while lower-effort groups did not (Pareja-Blanco et al., 2020).

Velocity loss is a technical way of measuring fatigue within a set — when your bar speed drops by 20–40%, you're working hard enough to trigger growth. You don't need a velocity tracker to use this finding. The practical translation: your working sets need to finish with genuine effort. Stopping 5 reps early on every set because it feels uncomfortable is not the same as doing 3 real sets.

For a full breakdown of how close to failure you actually need to get, training to failure has the numbers.

Groups allowing 20–40% velocity loss — the hardest effort — showed significant quad hypertrophy. Lower-effort groups did not.

— Pareja-Blanco et al. (2020). Velocity Loss as a Critical Variable Determining the Adaptations to Strength Training. Med Sci Sports Exerc.

The practical prescription: how to set up your squat sets

Here's how to translate the research into an actual session:

Goal: strength — Do 3 working sets at 75–85% of your 1RM (the most you can lift once). Rest 3 minutes between sets. Keep reps in the 4–6 range. This is your baseline. It's not conservative — it's what the evidence supports.

Goal: size — Do 4–5 working sets at 65–80% of your 1RM. Rep range of 6–12. Rest 2–3 minutes. Make sure the last 2–3 reps of each set feel genuinely hard — not grinding, but close.

Short on time — Do 1–2 hard sets, heavier than your usual working weight, taken close to failure. You'll hold on to most of your strength adaptations (Androulakis-Korakakis et al., 2020). Not ideal every week, but it works as a stop-gap.

Weekly target — Aim for at least 4–6 total squat sets across the week, split however your schedule allows (Iversen et al., 2021). Two sessions of 3 sets each is a clean, evidence-backed setup.

And don't forget warm-up sets — 2–3 progressively heavier sets before your working weight — so your joints and nervous system are actually ready. Those don't count toward your volume total.

Not sure how the squat stacks up against the leg press for quad growth? squat vs leg press has a direct head-to-head comparison.

How Planfit applies this

Planfit programmes your squat sets based on your goal — strength or hypertrophy — and your training level. It recommends working weight and rep targets per set, flags warm-up sets before heavy barbell work, and tracks your volume across sessions so you can see your weekly squat sets at a glance. When your current load stops being challenging, the progressive overload nudge bumps the weight up — so you stay in the productive zone without having to calculate it yourself.