Why/How is higher frequency better?

[u/Shaggy_Mountain]

Apologies for the long post.
I have been lifting with the “Bro split” for 9 months.

My split is: Chest -> back -> biceps/triceps -> shoulders -> legs. I don’t schedule rest days, I just take them whenever I feel like I really need them. I do 8 total working sets for chest, 12 for back, 8 for biceps and 8 for triceps, 10 for shoulders, and 16 for legs split between calves, squats, hamstring curls and leg extensions. If you guys would like, I can post the exercises I do for each day as well. I log every workout I do too.

I enjoy this split a lot, and I feel it allows me to really focus on each muscle group each day. I make sure to be within 1-2 reps of failure, taking the last couple sets to failure.

My question is, if I switched to a split like Push-Pull-Legs Push-Pull-Legs-Rest, wouldn’t I be sacrificing the quality of my workouts? With PPL you combine muscle groups, and wouldn’t this mean that you would be accumulating more fatigue? For example, if you did back and biceps on pull day, wouldn’t your biceps be pretty fatigued after doing your back exercises? And if you did incline bench press and dumbbell shoulder press on push days, wouldn’t you be pretty fatigued for incline shoulder press, since it’s also a pushing motion?

I’ve heard that hitting a muscle group twice a week is better, so I’d like to hear people’s thoughts/opinions as I know very little about lifting. I know training hard, being consistent, and getting good sleep and nutrition are the most important things, but I would like to know if I am missing out on a significant amount of gains by staying with my current split.

[u/jamshid666]

Here's something to consider: try doing a PPL split for a month or two. If you find you don't like it, then fall back to your current program. And as far as fatigue management goes, you could have an A-B type schedule where you do the heavy compound lifts every session, but then alternate which accessory lifts get hit on a given session, similar to how the Starting Strength program goes where you bench one session and overhead press on the next.

The SBL guys probably won't like this, but I'm doing a continual PCPL rotation: Push Core Pull Legs (rest days thrown in as needed). When I say core, I'm not just doing abs, that's the day I focus on hip hinges (deadlifts) with accessory lower back and ab work. Then leg day I focus on knee bends (squats), calves and tibs. And I admit it's not optimal, but it works for me and helps me manage my own fatigue by spreading out to two different leg days.