There’s one body of research that the article ignores: professional sports. Billions have been sunk into producing top tier athletes. Even if you won’t want to go professional there’s still a lot of benefit the average pleb can get out of the things trainers have learned, and a lot of their lessons can be found with a web browser and a search engine.
(basic theory: bust ass in a gym, eat the right ratio of fats/carbs/proteins, and drink a lot of water)