Tinuva
The Magician
While doing lets say bench press, your aim is to work on chest, but in the process you also work on triceps. To complete the bench press your triceps have to work pretty hard too. Which is also why you always work your bigger muscle groups before your smaller muscle groups, thats if you have them as part of your program/routine.Ignorance here - if you're hitting your biceps and triceps while exercising other groups, are you achieving the maximum result on the other groups? Ex. if you're hitting your biceps doing a bench press, you aren't achieving the optimum chest workout. Similarly hitting triceps instead of back on pull downs etc.
Again - this is ignorance asking. I don't claim to be a guru.
So to do lets say do tricep pushdowns before bench press is a very bad idea, but the other way around is perfect.
Now when you skip triceps/biceps for example, you not missing out on anything, in fact those muscles will still grow huge if you work hard on chest/back and actually improve on them.
What is bad, is to lets say skip legs altogether.