Research

Mixed

When resistance training is performed to volitional fatigue, muscle hypertrophy is independent of the external load used (high vs. low), provided volume load is matched or effort is equivalent.

You do not need to lift heavy weights to build muscle. If you use lighter weights (30-40% of your max), you must perform more reps (20-25) and push until you physically cannot complete another rep with good form. This effort-to-failure approach yields the same muscle growth as heavy lifting (70-80% max) done for fewer reps (8-12). Ensure you eat enough protein (at least 1.6g per kg of body weight) and train consistently 3 times a week.

GoodRefutesHIGH confidence
Our findings show that when higher- and lower-load RET is performed to volitional fatigue, neither load nor limb location mediates the RET-induced hypertrophic response
Matthew Lees et al. · The Journal of Physiology · 2025

Why this rating

Randomized controlled trial with a within-subject design, rigorous measurement methods (biopsy, DXA, ultrasound), and clear statistical analysis, though limited to healthy young males.

Source

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

Matthew Lees et al. · The Journal of Physiology · 2025

DOI 10.1113/jp289684

rct · n=20Cited 2×
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DOI resolved against Crossref · corpus check 2026-06-10

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