This is something I want some advice about, so please give me your opinion:
Recently I have thought about training each body part once every two weeks. I have noticed that if I train each body part once a week, it takes longer for my strength gains to increase than if I were to train each body part twice a week. For example, if I missed a chest training day and did it the following week instead, I would feel stronger and be able to lift more weight. The only thing I can think of is that I'm giving my body more time to recover.
I'm into high intensity training where I do 4-6 sets per body part, using heavy weights. The workouts are short but very intense. With high intensity, when you're doing your reps, you have to come to the point where you reach total failure. It wouldn't matter if someone put a gun to your head and threatened to pull the trigger unless you did 1 more rep, you must reach the point where you cannot do anymore. Such hardcore training requires plenty of recovery time. But let me also say this:
If you're training each body part once a week, most people think their muscles are getting 7 days rest. But in reality, that's not true. If you were to train shoulders on Monday and back on Thursday, your shoulders are only getting 3 days rest because training your back also involves your shoulders. Or if you were to train shoulders and triceps on Monday and chest and Biceps on Thursday, your shoulders and triceps are only getting 3 days rest because training your chest also involves your shoulders and triceps.
Most bodybuilders believe that you must train each body part at least once a week. But is this based on science, or do people just go along with it because everybody else is doing it? People seem to think that if they're muscle soreness has gone away after 2 or 3 days it means they have fully recovered. But if you're training high intensity, is one week really enough time to recover fully, considering that all your other workouts involve using the muscle you trained a few days earlier?