And he’s right. RTWT:
“Many people seem to have the wrong idea about weight training.
Whether you are in the gym for overall conditioning, for building muscle to prevent aging, or to become an actual bodybuilder, the process should involve working all of the skeletal muscles.
It appears to me — and this is a guess — that many people look at muscular men and see big arms to the exclusion of anything else. They then proceed to do isolation exercises, like biceps curls and triceps pull downs, to the exclusion of most other things.If your goal is health, work on all of your muscles.
If your goal is size and strength, work on all of your muscles.”