Before eating Sukuna's finger, and before being able to use cursed energy, Yuji Itadori is shown to have "superhuman strength" and "superhuman physical abilities", making him able to throw a lead ball with enough force to to bend a soccer goalpost. He's also said to be able to run 50 meters in 3 seconds, which would be a world record if true. What's the reason for this?
What's the reason Yuji Itadori has superhuman strength before being able to handle cursed energy?
The answer has been given in the manga. Spoilers below for chapter 143.
A sorcerer from the past named Kenjaku performed a series of experiments through the ages to "evolve" the human race and allow them to dominate curses. His own cursed technique allows him to take over human bodies, and a flashback has shown that he once possessed Itadori's mother. So he likely performed an experiment on Itadori, either as a fetus or as a baby, that made him superhuman. It should be noted that the author confirmed Itadori was similar in some ways to the Cursed Wombs.
As far as I know, it hasn't been confirmed yet.
But tbh I'm just an anime watcher, my theory would be that it has to do something with Sakuna in general. Maybe his parents had some deal with him, which could also explain why he is such a good vessel.
For this following question I could only give optional answers such as:
Itadori had a roughed up childhood and he must have training hard like Naruto to be the best of the best but not show it to others.
(or)
His parents must have been low-game sorcerers whom are not known much to the people around them (I mean not knowing they're identity) so they stay away from that city and he could have had that shred of cursed power from the beginning where he trained it unknowingly and only his grandpa knew what he is capable of
There are possibilities
Personally I think it had something to do with his parents. Not much is known about Itadori, including his parents. Before his death, his grandpa tried to tell him something about his parents, whether it be who they were, or what happened to them. But Itadori cut him off and never let him finish.
