I mean like... For expert bodybuilders, expert powerlifters, and basically any educated athlete who takes the science of what they do seriously... Do you all believe that at this point, there's no more discoveries to be made?
We've mastered anatomy hundreds of years ago. We've decoded nutrients at the level of the molecule. Strength training methods have barely changed for the past seven decades. Kinesiologists have identified all conceivable types of human movements such as picking stuff from the floor, squatting, pressing, et cetera.
What else is there discover? Seriously. Better steroids?
Gene therapy is really just cheating so that doesn't even count.
I mean, it may be possible to eke out some more through genetic engineering, but we've pretty much hit max or close enough to that.
As for cheating...
Powered Exoskeletons
There is a natural limit to what the human body is capable of. The only way beyond that is new bodies.