Why did deku not do any Physical training, if he were determined to become a hero?

From what i remember deku said ¨even if i don't have a quirk i can still give it my best at the entrance exam¨ if deku was determined to become a hero no matter what and try at the entrance exam despite not having a quirk, why not do the bare minimum and get a gym membership and start working out before the exam?

perhaps this was explained and i completely missed it, i do remember he once said *there was one point where i completely gave up on my dream* when fighting gentle criminal, so maybe thats why?