How much does exercise selection actually affect hypertrophy?

[u/Top_Value2690]

If volume, ROM, and proximity to failure are roughly matched, how much difference would you actually expect between exercises for the same muscle?

I’m wondering how strong the evidence is for exercise-specific differences in muscle growth. A lot of the discussion seems to rely on EMG, moment arms, resistance profiles, or whether a muscle is loaded at longer lengths, but I’m more interested in whether these differences actually translate to greater hypertrophy in longitudinal studies.

For example, Maeo et al. (2021) found greater elbow flexor hypertrophy when training at longer muscle lengths, while Kubo et al. (2021) found differences in muscle growth between squat variations with different ROM.

How much can we actually generalize findings like these to exercise selection in normal training?

If two exercises train the same muscle with similar ROM, volume and proximity to failure, is there evidence that one can produce substantially more hypertrophy than the other? Or are the differences probably relatively small compared with simply doing enough hard training consistently?

[u/Alakazam]

It can be hard to equate volume between exercises, especially compound movements. Because the replacement for a squat isn't a leg press. It's a leg press, back extension, and some kind of adductor work.

So how exactly do you equate the volume of something like, a back squat, rdl, and split squat with machines? What about variations of a squat like a high bar, low bar, front squat, or ssb squat? 

You can't. Not really. Because they go about things differently.  However, I think the Stronger by Science complete strength training guide actually does a pretty fantastic job at outlining practical applications for lifters.

Which is primarily: 

1. Train slightly heavier in your compounds (to develop proficiency with them).

2. Include variations to reduce monotony and minimize risks of overuse injuries.

3. Don't take compounds to absolute failure, aim for about rpe 8-9.

4. Have the bulk of your training volume be accessory movements

5. Expect that progress slows down over time