Even if one exercise uses more muscles than another, both can make the same muscle grow just as big if you train hard enough.
Scientific Claim
Compound exercises involving greater total muscle mass do not produce superior hypertrophy in target muscles compared to isolation exercises when training volume and effort are equated.
Original Statement
“Back squats train a larger amount of muscle mass versus hip thrusts. Yet, the paper ultimately observes similar glute max hypertrophy between both exercises. Furthermore, we'll see how some of the data we're about to examine next also relates to this area. Nevertheless, with all this in mind, I currently think that whether an exercise is bilateral or unilateral isn't a critical consideration for hypertrophy.”
Context Details
Domain
exercise
Population
human
Subject
Compound and isolation exercises
Action
produce
Target
equivalent hypertrophy in target muscles when volume and effort are equated
Intervention Details
Evidence from Studies
Supporting (1)
Hip thrust and back squat training elicit similar gluteus muscle hypertrophy and transfer similarly to the deadlift
Even though squats work more muscles overall, they didn’t make your butt grow bigger than hip thrusts did—when both exercises were done the same number of times and with the same effort.
Contradicting (3)
Comparison of Muscle Hypertrophy and Strength Adaptations Induced by Back Squat and Leg Extension Resistance Exercises.
Even though squats work more muscles overall, leg extensions made one thigh muscle grow more than squats did — proving that just doing big compound moves doesn’t always make your muscles bigger than isolated ones when you train the same amount.
Cluster sets and traditional sets elicit similar muscular hypertrophy: a volume and effort-matched study in resistance-trained individuals
This study didn't compare big multi-joint exercises to single-joint exercises — it just compared two ways of doing the same exercises, so it doesn't tell us whether compound moves build more muscle than isolation moves.
Volume-equated high- and low-repetition daily undulating programming strategies produce similar hypertrophy and strength adaptations.
This study found that lifting heavy and lifting lighter weights — both using big multi-joint exercises like squats and bench presses — built muscle just as well when the total work was the same. That means big exercises aren’t worse than single-muscle moves for growing muscle, which goes against the claim.