Yeah bro, I will try to explain ok? My English isn't THAT good, sorry for that.
If you train in the morning, and you train heavy and with high intensity, the training demands A LOT from a natural human body. Like a guy said it before in here, you should train fast and furious. The only thing that'll make you grow after a workout is A LOT of rest. You won't get that rest, if you take your body in a catabolic phase 2 times a day. Because that is what you are doing with training, you are destroying muscle tissue. And with the right amount of rest those muscles will heal, and will get bigger. But with this plan that you have of training 6 days a week, you are more focussing on destroying muscles than to build them. I have tried things like that too. But it's SUCH a strain on your body and indeed on your nerve system that you WILL be overtraining. You're only building muscle, and the next time you are making them smaller because they didn't get the chance to recover.
And there's something else, if you only train 1 muscle at the time, it's obvious that you will damage that muscle too much. Because you will go into the gym with the attitude: I only have to train chest this morning, yeah, so I am gonna throw bombs on it. And before you know, you are doing like 4/6 exercises and 3/4 sets per exercise only for a LITTLE chest muscle. You will damage that muscle so much, that it will never get as big as it could be. ESPECIALLY if you're training 3 days on and only 1 day off. That's how pro's train, but everybody knows that won't work for us. And if you don't make good gains with each muscle only 1 time a week, it's possible that you don't train heavy enough. That you are concentrating on the volume too much instead of the intensity. If that's the case then I can understand that you make more gains with training each muscle 2 times a week. But the flipside to that coin is, that you are like 3/5 hours a week EXTRA in the gym to get those gains
is that worth it?
just try something like this, It'll be worth trying believe me:
monday legs and calves:
leg extension 2 sets of 20 SLOW reps.
squats 3 sets of 6/10 reps
stiff legged deadlift 2 sets of 10/12 reps
sitting calve raises 3 sets of 20 SLOW reps
if you are doing it with the right intensity, and heavy enough, you WON'T come back the same week to train legs again
you understand what I am trying to say?
tuesday chest, arms and abs
benchpress 3 sets of 6/8 reps
incline dumbbell press 2 sets (first set light, and the second set, give it all you've got)
barbell curl 2 sets of 8/12 SLOW reps (especially focus on the slow negative reps, just try it, you will be amazed at the gains on you're biceps)
one arm dumbell preacher curl 1 or 2 sets of 10 slow reps
triceps cable pushdown 2 sets of 10/12 slow reps
sitting 1 arm dumbell behind head triceps extension 2 sets of 6/10 reps
crunches 3 sets
And now 2 days of well-deserved rest, you're gonna need it if you trained with the right intensity. With those 2 days off you will be so well recovered and motivated that you will train with ferocious intensity on friday.
friday back, shoulders and abs
reverse grip cable pulldown 2 sets of 8/10 slow reps
bent-over barbell rowing (you can also do this on the smithmachine, I feel that exercise 2 times better if I do it on the smithmachine) 3 sets of 6/10 reps.
neckpress 3 sets of 6/8 reps
side raises 2 sets of 10 SLOW reps
shrugs 2 sets of 10 slow reps
crunches combined with dumbell side bends 3 sets of 20 reps
don't be prejudiced and just try it, if you don't like it after only 1 week I will be surprised!
).
If you don't want to make ANY kind of gain you should do this. This statement on itself is a proof that you WILL be overtraining. Especially if you're gonna train with much intensity (I think that that is what you do) your body needs rest!