Whether you lift heavy weights for fewer reps or light weights for more reps—as long as you push until you can’t do another rep—your muscles grow about the same amount.

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Evidence from Studies

Supporting (1)

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Resistance training load does not determine resistance training-induced hypertrophy across upper and lower limbs in healthy young males.

Randomized Controlled Trial

Human

2025 Dec 31

When people lift weights to the point of exhaustion, whether they use heavy or light weights, their muscles grow about the same — it’s how hard they try, not how heavy the weights are, that matters.

Contradicting (0)

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No contradicting evidence found

Source Study

Resistance training load does not determine resistance training-induced hypertrophy across upper and lower limbs in healthy young males.

Score: 46

DOI: 10.1113/JP289684

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Whether you lift heavy weights with fewer reps or light weights with more reps—as long as you push until you can’t do another rep—your muscles grow about the same amount.

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