as for your 3 day a week
why not this
A: chest bis tris abs
B: legs + calves
C: back shoulders
im hoping your b and c day are at least a good day apart. lower back lower back gotta watch that
If you can do your best to get in the gym 3 days a week, this changes things. 5x5 would still apply here as well as an UB/LB, HST or full body split. Personally I just don't see what can be achieved in 2 days.
The main thing is to get in and lift as hard and frequently as possible with the limitation of how well you can recover from said same. I'd personally prefer to see some sort of fullbody program, but most people who claim they do splits are actually doing fullbody (deadlifts on back day, etc). Program around work where possible so that you will actually get the most out of the training.
The recovery phase is somewhere between 24-36 hrs, unless you have overdone the training in which case muscle damage (think painfull DOMS) can last for a week (or more). So how often you train is dictated by how much stimulation/annihilation you give the muscles. Muscle atrophy after 48hrs is a little overstated. While you are rebuilding or laying down new tissue you don't tend to use protein stores for energy (read muscle atrophy on a small scale), once recovered you do. But this tends to be a maintenance thing, you will maintain more muscle as long as calories are adequate to not require protein for fuel. So atrophy will only occur as part of long term homeostasis when the body no longer needs more muscle, this takes weeks! Just remaining active will help retain a lot of the muscle.
But while you state that you will use little protein stores if any for energy output to repair, if you train and result in heavy DOMS...essentially you will produce the same. So, if the trainee happens to over-reach, causing any DOMS really you're using a) different motor units and/or b) no or delayed growth. I said a FB routine would be fine. However, stating "how often you train is dictated by how much stimulation/annihilation you give the muscles" is contradictory. If you over do it and cause the DOMS (as in sore for days after)...there will be little hypertrophy. Protein may not be used as an energy source, but energy will be used to repair the muscle cell membranes (sacrolemma), first, then hypertrophy. Which is far more lengthy, making gains delayed. That or you simply executed different fibers.
I also don't think people who use split work focus on their entire body. Deadlifts are a compound exercise but the load put on each muscle doing the lift differentiates. The load placed on the legs/lumbar/back, etc are far stronger than that on the biceps. They are a supporting mover.
Tim definitely see what you're saying. I think, if I'm understanding correctly that muscle atrophy in 2 days won't be very much as long as you maintain your calories and remain active, which shouldn't be a problem. And sorry for the incorrect hours of atrophy, I remembered it being around those numbers.
Again I may be off base, but debating's are how you learn!
The hypertrophy is going to be less under the heavy DOMS (once a week training, or whatever) scenario. The reason for going this route though is that it does result in less atrophy as muscle repair and synthesis occurs for a longer period than would occur normally from training. Training that works on stimulation requires more frequent bouts of exercise, annihilation less. Stimulation is a better idea but not always pratical.
FB routines are meant to address the frequency issue without having to have more training days. And yes I see your point about specific muscle groups getting more work (which will be somewhat individually specific), but the body as a whole reacts from a biochemical standpoint. Thus larger exercises will have a larger effect on the anabolism/catabolism processes and guard against strength and muscle losses (within reason).
Hopefully IS and others will chime in here, would could get a really good discussion going KM.
And of course, some's responsiveness is far superior when done in split loads, say once twice/wk while some increase frequency all week.
I feel you Tim, hopefully others will come in!
Squats,deads, incline bench
im following the template and it told me to lower the weight for squats
so i did it with a 25lb plate per side, and a 5lb per side.. 5x5s
also deads, regular deads im having a tough time with, the weight is easy only 135lbs
it just how to not hit the knees when coming up.
5x5 with 135s
incline flat bench
3 sets of 5, then last 2 sets 3-4reps...135lbs