Once a week per muscle is not enough
Why splitting your volume over two or three days beats one hammering.
The signal fades faster than you think
After you train a muscle, protein synthesis rises and is back to baseline within a day or two. If you only hit it on Monday, the rest of the week it is building nothing. Two sessions per muscle give you two peaks, and in practice that means slightly more muscle for the same total sets.
It also fits better
Twenty sets of legs in one day is four exercises with the last sets crawling and a week of soreness. Ten and ten across two days is quality work. The total rules, but how you spread it decides how much of that total is real work.
What doesn't change
Training more often does not replace volume or effort: three days of three easy sets is still not much. And if you can only make it twice a week, an upper-lower twice beats trying to cram the whole body into one day.
More on Hypertrophy
How many sets a muscle needs per week
The number that decides whether you grow. Not four, not forty.
Close to failure, not always to failure
What RIR is, why you leave one or two reps in the tank, and when to push.
Progress without stalling: double progression
When to add weight, when to add reps, and why not both at once.
How long to rest between sets
Two minutes is not a quirk: it is the reps on your next set.
Protein: how much and how to spread it
The daily total is what matters. The exact timing, far less than you hear.
Stalled: what to check before switching routines
It is almost never the routine. Five things to check first.
This is general information written from the training literature, not medical advice or a personalised plan. If you take medication, have a health condition or something genuinely hurts, the person to ask is a healthcare professional.