from FT to MDT

[Scott Stevenson]

I 

there's more to it than just "MPS lasts for 48hr," of course

I would make a question about it.
The catabolic issue apart, I suppose that we should consider 2 factors: 1) how long MPS stays elevated; 2) how much MPS stays elevated.
Some years ago, I read a paper. 
It measured MTOR after workout, comparing low and high frequency workout (the volume per session was the same while the weekly volume was, obviously, different). The study concluded that the MPS doesn't last for more than 48 hours but in the low frequency group the Mtor levels were higher compared to high frequency group. So, in the 48 hours range, in the low frequency group MPS was  higher than the high frequency group (again, in 48 hours, not weekly).
I can't find the research but would like to know if u think that makes sense.

Doesn't remind me of a study that I can recall. "mTOR levels" doesn't tell me enough about the methodology that was used.  On the one hand, MPS measurements at the start of a program don't predict muscle growth, e.g., 1.  Mitchell CJ, Churchward-Venne TA, Parise G, Bellamy L, Baker SK, Smith K, Atherton PJ, and Phillips SM. Acute post-exercise myofibrillar protein synthesis is not correlated with resistance training-induced muscle hypertrophy in young men. PLoS One 9: e89431, 2014. 301 Moved

whereas on the other hand, if this was a training study, they'd hopefully have measures of muscle growth.

 

BTW, Training alters MPS:
1.  Kim PL, Staron RS, and Phillips SM. Fasted-state skeletal muscle protein synthesis after resistance exercise is altered with training. J Physiol 568: 283-290, 2005. 

You might find this interesting:
1.  Damas F, Libardi CA, and Ugrinowitsch C. The development of skeletal muscle hypertrophy through resistance training: the role of muscle damage and muscle protein synthesis. Eur J Appl Physiol 2017. 

II

"more room for growth"

I describe my feeling, nothing more.
the pump after a high(er) volume session (MDT style) is better than the pump I get after a total body low(er) body training.
I don't think that pump is good per se but using "pump workout" is  like creating "more room for growth" so it makes sense to me having some high volume sessions during the year.
I remember the ABCDE program guy (he had a strange sweedish name) said that the "pressure" of connective tissue is a limiting factor for muscle growth and suggested that the stretching of connective tissue (using stretching, pumping the muscle, loading the muscle with nutrient) can speed top muscle growth.

Torbjorn Akerfeld, I believe.  So this is an argument by authority?... 

If stretching CT is what you're looking for, why not finish with pump set and stretch safely to increase flexibility

-S