is it necessary to do exercise that target only one muscle a day

Question

I live in India and have joined 4-5 gyms in last 4-5 years in different cities. Every time people do and also suggest me to do exercise that target only one muscle per day. e.g. on Monday only biceps exercise, on another day only triceps exercise and shoulder exercise on any other day, i.e. to do exercise that target only one muscle each day.

I exercise in the gym daily for 1 hour in the morning and 30 minutes at night after dinner and before going to bed (most time of the day I just sit on a chair as I'm an IT developer). I want to build or grow muscles mostly on bicep, triceps, shoulder, chest, wings (not abs, back, and leg).

So is it really necessary to do exercise targeting one muscle a day like I mentioned above, and if it is necessary, do I have to do exercise targeting only one muscle at morning and night on the same day, or can I target one muscle at morning and another at night? How much time of rest should one maintain between two different kinds of muscle exercise? Or is this all just a myth?
Also if I do biceps and triceps together then will the benefit of exercise gets reduced?

Answer 1

You are correct to be suspicious of the "one muscle a day" prescription. While that method works fine, it is perfectly possible and very productive to do whole-body exercises every time you work out.

Many Olympic weightlifters do what's called Bulgarian training, which is training five or more days a week, sometimes several times a day. They use whole-body exercises like deep squats, presses, cleans, jerks, and snatches. They get very strong and very big using this method. However, their goal isn't to look good, but rather to lift heavy weights in the snatch and clean & jerk.

Another method is simply not working out every day. If you lift three times per week instead of every day, you can be more sure that your body is getting enough rest. Muscles and people need to rest in order to grow, and it's hard to split up your workouts completely. There's nearly always some overlap between muscle groups no matter how you try to work one while resting the other.

Answer 2

If you were to train every muscle in the body, I only count the "show off muscles" here, like biceps, triceps, abs, etc not all in the body, you would train each muscle about once in a week, if not even less.
It is widely accepted that muscles need some rest after you train them, but for achieving most muscle growth you should train them in when they are in the recovery phase. When this phase begins depends - as far as I remember - on the person and the muscle, but is generally said to be about two days later.

Depending on what results you want to get it might be a good idea to use isolation exercises instead of compound exercises, that is focusing on a specific muscle instead of a bigger group or the whole body. But training it only once a week would probably not get you the results you want.

My approach, if I would go to the gym twice a day would either be to think of four muscle groups I want to train (eg, abs&back, shoulders, arms, legs) and alternate between those sub-plans, If my goal was not too specific I would rotate them each week.
Another possibility would be to do cardio in the morning and muscle training in the evening, with two focused sets.

Again, it heavily depends on your specific goals how you show arrange your training.

Answer 3

Once a week workout's never worked for me. I have wasted years doing that non sense. For me it only gave starting results and then left me making little improvement. I felt that this was not enough workout and working out each body part twice a week was much better. You could also try alternative routines like Starting strength OR GVT and than lose the excess Fat. I also don't agree with your approach to build only show off muscles, why ignore something as important as Legs. IMO exercises like Deadlift/Squats have hormonal affect which improves overall strength and recovery.