I do a lot of strongman conditioning type training (in the offseason and preseason for football) (heavy sled drags, pulling trucks with harness, tire flips, farmers walks, log presses, etc...) but don't really do it for muscle hypertrophy effects directly, but will say that I have been very surprised on how much size it has helped me put on since starting it. My upper back/traps and forearms have definitely blew up after handling heavy farmers walks for long periods of time over the last few months, and my quads have gotten a bit bigger from the heavy sled dragging. Plus have gotten very lean from all the activity. If you're a bodybuilder then there's not much reason to do it (it certainly wouldn't hurt though), but if you're an athlete then I would say it would def help you provided you played a sport like football or baseball, etc...