Well throughout my undergrad, I NEVER had more than 2-3 classes in a day, but we might do things a bit differently in CA. And as far as studying goes, my “argument” still makes sense. In highschool, when you are taking 6 classes each day, you dont have homework/studying for one class per night. You have to do EVERYTHING each day to stay on track.
And im sorry X that you dont buy into motor learning, or dont understand its effects, but its very important. Even “high level” bb’ers and pl’ers are not “masters” when it comes to lifting. Genetics has VERY little to do with how quickly you are going to learn a lift. I’d actually argue that a LOT of the biggest guys have very good genetics, but very poor motor skill, but I definately dont want to get into tha right now.
The school analogy is a very interesting one though. And it really goes along with learning anything. You start out training everything at once, frequently but for low durations. And you start with the fundamentals. Then as you get those “down” you start to add the “little things”, this would be like addint plays in baseball, or creative writing, and calculus in school. You have to have a good foundation of the basics first, and then as you schedule gets more demanding, you may switch things around to focus more time on areas that you want to develop.
So, when you graduate high school and pick a major, then you start to focus specifically on that area, because nobody wants to be a “jack of all trades, master of none”. At this point, you begin to have more and more “complicated” factors going into your schooling and larger volumes of work, that are spread out more.
Undergrad classes were usually 50-75 minutes, and you might have 2-3 per day, but when you get past that, the classes are 2.5-3 hours and you certainly must do less.
So if you dont buy into the motor learning aspect of it, thats fine. Just click the back button, but if you do, then the following sorta makes sense.
You start training with a very high frequency, low load, and low volume. You might do TBT 5-6x per week, that is just 5 sets of 5 with a 10RM. And this would just be the basics. Bench, squat, deadlift, press, maybe clean, snatch, and jerk, if you are going to go into weigtlifting. Then when you develop a level of proficiency in those lifts, you start to load them, and cut down on the frequency. If you are going to train abut 3x per week then you keep the TBT, if you are going to go more, then a split will be necessary. After that, you are sorta at a middle school/high school level, and you start to add some assistance exercises and isolation moves. You load those as well, and by the time you are at the senior in highschool level, maybe undergrad level, you are still training with all of those basics, but you can clearly see areas that you want to FOCUS on. You start to put more focus on lagging muscles, and as you get to the post bachelor level, you start to use “special methods”. This is where things get complicated, but stuff like drop sets, and glycogen supercompensation, etc.
The analogy works pretty well, and you see that although there is a trend of progressively reducing frequency as you become more proficient, there is nothing definitive on split vs. TBT. When you need a higher frequency of training, like training each lift 3-5x per week, it just makes sense to do TBT, because how else will you fit that frequency in. You could do a split with multibple sessons per day (I know CT has done this) but not everyone has that amount of time. You figure if you have 3 main lifts / bodyparts to hit 3-5 times per week. If you are going to split them up, then you are going to have to hav 9-15 sessions. So TBT makes sense there, but doesnt have to be the only way.
Then when your “optimal” frequency gets down to 3 or less times per week, and you have more assistance/isolation exercises, you have a bit more options. And I really dont think it matters that much as long as you are still hitting those main exercises 2-3 times per week. The isolation stuff really isn’t that demanding and the main lifts are much more important, so as long as you are progressing on the main lifts, it doesn’t matter how you train the accessory/isolation stuff.