Research

Mixed

Single-joint resistance exercises provide superior hypertrophy for specific muscle groups (e.g., rectus femoris, hamstrings, calves, biceps, triceps) compared to multi-joint exercises alone, necessitating their inclusion for optimal muscle development.

If your goal is maximum muscle growth, do not rely solely on compound lifts like squats or bench presses. Add specific isolation exercises for muscles that are under-stimulated by compounds. For example, add leg extensions for the rectus femoris, leg curls for hamstrings, and curls/extensions for arms. This ensures every muscle gets adequate mechanical tension and metabolic stress for growth.

GoodSupportsHIGH confidence
Accordingly, Ema et al. observed that twelve weeks of knee extension training produced greater rectus femoris hypertrophy (~22%) compared to the vasti muscles (≤10%)... These results indicated that while it was possible to achieve upper limb hypertrophy using multi-joint exercises, single-joint exercises may confer additional muscle hypertrophy.
Ewertton de Souza Bezerra et al. · Brazilian Journal of Kinanthropometry and Human Performance · 2021

Why this rating

The claim is supported by multiple longitudinal studies cited in the text (Ema, Kubo, Earp, Barbalho, Mannarino) showing statistically significant or clinically relevant differences in hypertrophy, though the paper itself is a review.

Source

Resistance training exercise selection: efficiency, safety and comfort analysis method

Ewertton de Souza Bezerra et al. · Brazilian Journal of Kinanthropometry and Human Performance · 2021

narrative_review
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