
For the last 1.5 years I've done a 4 day split with a rest day every 4 days. Day 1: chest, biceps, brachialis. Day 2: triceps and shoulders. Day 3: back. Day 4: legs and forearms. I do abs and and obliques everyday, but different exercises. I aim for 0.85g of protein per lb, I do 3 sets per exercise, rep range is 8-12, but for calves, abs, obliques, forearms, side delta, and rear delts I increase that to 8-24. I burn 200cal on treadmill everday too. My back day is also volume heavy with
6 exercises. I also do 4 tricep exercises on my arm day with 3 shoulder exercises (1 per delt head). I take 3 minute rest in between sets and in between exercises since I want to do a lot of volume and lift heavy with max effort since my frequency is low. I go to absolute total failure on my last reps no reps in reserve.
Favorite exercise is definitely 1 arm assisted pullup or dumbell incline bench press. I do every exercise individual sides, like I do 1 arm at a time on cables and do dumbells instead of barbells. My scoliosis is really bad and shifts the entire left side of my body's angle, so I'm always adjusting my form to not create muscle imbalances
I know it's suboptimal but that doesn't even matter every gets worked up with being as optimal as possible when the most important things are effort and consistency. I enjoy this split so that's why I'm able to stay consistent. I see ppl at my gym for the last 2 years who have made little to no change while I'm successfully progressively overloading every exercise every 1-2 workouts. Optimization is overrated unless you're competing at the high levels.
I could do a 3 day split to increase frequency but frequency is less important that overall volume. U can hit your volume for a muscle in one day as long as you rest in between properly. Also everyone's body is different and what's optimal for one person isn't optimal for others. The only reason I even look this way because I switched to a 4 day split. I was stalling hard on 3 days 2x a week. More rest time is needed depending on how advanced the lifter is, how hard they train, and what muscle.
I was using "optimizing" lightly—you do not need to be doing 4 exercises targeting the same muscle group. You're getting close to zero gains out of anything past 2 exercises for a muscle group. That's the biggest issue. The time you spend doing your 2nd/3rd/4th tricep exercise is time you could be spending hitting another muscle group. You really only need 2 sets of a given exercise at all, or 3-4 if you're hitting 2 different compound movements in the same day.
The other thing is, there is not a single muscle on your body that responds differently to how many reps you do. They're all mostly the same. You could make a case for doing up to 12 reps, but you really only need up to 8, and 24 is just insane. My dude, you are spending twice as long in the gym as you need to be, and getting ¼ as much useful work done as you could be