I'd posit that it's being done already, though on a much smaller scale than I'd imagine you are portraying. Every elite athlete that does wind tunnel testing, has been fit by a computer algorithm (yours truly among many thousands of others), and has been fitted with biological sensors that are collecting/storing data; all the above and more are data points entered into algorithms and computer modeling programs to study and track the limits of human performance and fitness.
The geeks and scientists that study and understand the output are the ones pushing the elites to tweak their form, nutrition, perceived exertion, et al... The one caveat being that no two athletes are alike and every single one will have bio-characteristics that are limiting or surpassing others.
Take cycling for example (my obvious go-to); there are body types and physiologies better suited for climbing, sprinting, chasing, escaping, and enduring but, without significant biological modification; a sprinter will never be a good climber and vice versa.
A significant factor in human performance limitation is shutting off the brain's naysayer voice and ignoring the pain. Some of that is discipline through experience, some of it is science using what "legal" enhancements are allowed, and a lot of it is time. I think it was Eddie Merckx that said it best
"Cyclists live with pain. If you can't handle it you will win nothing."