Who are these twig muscled guys to talk? What do they know about the "tipping point" of too much , lol. The body is capable of a hell of a lot more than they say.
Stuart McGill has coached a lot of athletes. Just look at the testimonials on his site lol: www.backfitpro.com/testimonials/ Note that Stan Efferding is on there, if you care about the size of the person talking. You don't need to be huge in your 60s to have studied the body for decades prior to that.
Stuart McGill has coached and worked with Ed Coan and Bill Kaz and many others. You know, the greatest strength athletes who have ever walked the face of the earth.