So me and a friend go to the gym and we work out our entire body in 1 day. I told him if he wants to focus on 1 muscle group more and wants to go more tot he gym he can just do 1 muscle group per day, common logic ofcourse, he agreed, but he said he would rather do all of them in 1 day, but he wants to go 4 days in 1 week doing every muscle group each week. I can understand why though, he is very skinny and only recently he has started seeing results (he is getting more muscular etc), so he is pumped etc.
But what are truly the benefits of doing 1 muscle group each day? Because personally I don't feel like doing 1 per day, I would rather go 3 times per week and do all in 2 of those days and cardio on the third day.
So what I am asking is: Which one is better to do, 1 each day, or all of them doing that 2-4 days a week.
I know thread title is vague.