Research vs Bro-science

Do You Really Need the Big Three? 'Free Weights or Nothing' Myth vs Research

Published: 2026-07-06

Written by: Hirotsugu YoshimuraReviewed by: Tomonobu Someda

The 'Big Three' — squat, bench press, and deadlift — are often called the backbone of strength training, and you'll hear claims like 'you can't grow without free weights' or 'machines are for beginners.' Others would rather stick to machines because of knee or back concerns. So are the Big Three and free weights actually essential? Let's look at what the research says, point by point.

Let the data settle it.

Round1

Can you only build muscle with free weights (the Big Three)?

What's said

ジムでの通説、YouTubeフィットネス系コンテンツ

Machines are on fixed rails and too easy, so they don't work. Real hypertrophy only comes from free-weight compound lifts like the squat, bench, and deadlift. Machines are just for beginners or finishing touches.

What research says

For hypertrophy, several studies report little to no difference between free weights and machines.
A systematic review and meta-analysis by Haugen et al.
(2023; 13 studies, 1,016 participants) found no statistically significant difference in muscle growth (SMD -0.055, p=0.751) and no difference in jump performance.
An 8-week RCT by Schwanbeck et al.
(2020; n=46) likewise found equivalent increases in muscle thickness between the two.
When effort and volume are matched, growth doesn't hinge on 'free weights vs machines.'

Verdict

For healthy general trainees, 'you can't grow without free weights' is not supported for hypertrophy. Machine-based training can build muscle just as well when you train hard with adequate load and volume. Think of equipment as an option, not a prerequisite for growth.

Confidence:Strong evidence

Round2

Are free weights and machines equal for building strength too?

What's said

パワーリフティング・競技系コミュニティ

If you want to get strong, free weights are king. All the machine work in the world won't make your barbell lifts go up.

What research says

There's truth here: strength gains are largely specific to the way you train.
Haugen et al.
(2023) found free-weight training favored free-weight tests (SMD -0.210, p=0.023), while machine training tended to favor machine tests.
In Schwanbeck et al.
(2020), machine-bench 1RM rose +13.9% in the machine group vs +8.6% in the free-weight group — training that matched the test improved more.
But this is about skill specificity in the movement, not about how much muscle you build.

Verdict

'To get strong at the barbell, train with the barbell' holds up. If your goal is competition or a specific 1RM, practicing that exact movement (free weights) matters. But if you just want bigger muscles, this specificity barely matters.

Confidence:Strong evidence

Round3

Should people with knee or back concerns avoid the Big Three?

What's said

一般的な不安・SNSの体験談

The Big Three are dangerous for your joints. They'll wreck your back and knees, so it's better to avoid them.

What research says

There's no strong evidence that the Big Three are inherently dangerous; most issues trace back to form, load selection, and progression.
And because hypertrophy is comparable between free weights and machines (Haugen 2023; Schwanbeck 2020), someone with pain or mobility limits who chooses machines or guided paths isn't giving up much in terms of growth.
Equipment choice can be a rational call that prioritizes staying consistent — not a compromise on results.

Verdict

The Big Three are neither mandatory nor inherently dangerous. If you have a prior injury or concerns, it can make sense to use machines or alternative exercises to keep training rather than forcing the Big Three. If you have pain or uncertain form, work with a qualified coach first. This article is educational and not individual medical advice.

Confidence:Mixed evidence