Rest time and training other muscles

Question

I am doing althernative days training I mean one day Chest/Arms/Abs the other day Back/Shoulders/Legs

I know rest is important for muscle growth

So If I trained my chest/Arms/Abs on Monday idially the muscles will have 48 hours rest till the next exercise time

But actually when I train my back the Biceps get used as well Like when I do Lats Pulldowns, I fell Biceps are fatigue a little too

So Should this be consider as rest time as muscle get trained lightly

or by rest we me dont use this muscle as much as possible?

Thanks

Answer 1

To work around this issue, you can divide your routine into push+abs, pull+legs. Because you're right: many exercises for your back also include your biceps. This is because your back is mainly used for pulling movement, and your biceps as well.
Your chest is mainly used for pushing movements, and your triceps as well.

For this reason, triceps and chest go together and biceps and back.

Answer 2

There are primary movers and secondary movers. You won't have any problems with that split. The aim of muscles are to work :)

By that logic, we should not climb stairs after we trained legs. Do not get into that much detail, just go with common sense.