@ Chris Colucci and nighthawkz: thanks for the answers! It seems you both say “it depends on the individual”. And I guess I was grappling with how all of this applies to me.
I think the issue I was considering was the following…
If in general a higher frequency is better, and also if in general a higher volume is better, how do you combine these aspects into training? There are many different programs out there… and I mentioned a few. What I noticed is that generally programs with a high volume, have a lower frequency and programs with a higher frequency have a lower volume.
Before I posted, I was considering if there was an optimum in this trade off? Also, why not combine a high volume with a high frequency? I think this would probably only work if you periodize it and add in a deload after a stretch with high volume/high frequency.
These thoughts were triggered by this article:
HIGH FREQUENCY TRAINING FOR A BIGGER TOTAL ? RESEARCH ON HIGHLY TRAINED NORWEGIAN POWERLIFTERS by Greg Nuckols
BTW, I was pretty clueless back then, but when I did a full-body 5x per week (weekends resting) I did a week with 3x15, a week with 3x10 and a week with 3x5 and a week with 3x10 reps (and repeat) and I alternated daily between 2 different routines. As I said, fast results, but with several overuse injuries and burnout followed by quitting lifting for years at the end of the summer. And to answer your question Chris - yes I think I can replicate these results at 36 with a bad back - in particular the injury part - but I’m interested in finding something sustainable that won’t lead to injury and quitting.
BTW after some more digging I found this article, which answered a bunch of my questoins:
“The influence of frequency, intensity, volume and mode of strength training on whole muscle cross-sectional area in humans” by Wernborn, Augustsson and Thomee.
Results are all over the place with no discernible (to me at least) optimum with respect to volume, frequency, etc., which confirms what you both have said.