Clearly he will fall apart if he does full body 4x a week.
Chad Waterbury wrote extensively on higher frequency training. Some of the things he wrote suggested even training total body up to 8x/week! His 10/10 book also contained a full HFT program with 5x week total body training
OP, YES you can do it. Your progress will depend on controlling the volume carefully (both in set x rep schemes and total training volume). You’ll also have to vary your movements each training session and get a ton of food and sleep. Read the Waterbury stuff on HFT, and see what you can do.
If you’re more of a newb (like me!) then maybe a 3x week full body or an upper/lower split would work better. I had a lot of success (and fun) doing Defranco’s west side for skinny bastards.
Best part of that article:
“Training your entire body for, say, four sessions each week will build up your overall fitness levels much higher than one set of a handful of exercises taken to failure every seven days.”
There’s also a 4x/week full body program laid out towards the bottom.
For some reason I was thinking the topic was about pure heavy lifts, and not including breakdowns like CW discussed in his article. The routine in that article looks amazing, and I’m really tempted to try it out now after reading about it once I’m done with mine.
Also if you consider Oly lifts as total bodies, then literally you would be doing total body workouts 6 days a week if you went with a Oly routine.
My fault for the stupid comment.