Hideki is having trouble completing long workouts. what does he need to improve?

hydration
stamina
knowledge
power

I'm pretty sure he needs to improve stamina.

I know that sometimes people would say power but it only makes Hideki more tired if he/she (I don't know the gender sorry!) uses more power.

Hope I helped at least a little bit! :)

Answerits to good to be true,the terms of the deal are vague,you are being pressure to make a deal,claims they are affilliated with the government;