Of Course Ezio Is Going To Have Wrist And Hand And Arm Pains. He Wasn't Trained In The Art Of The Assassins

Of course Ezio is going to have wrist and hand and arm pains. He wasn't trained in the art of the assassins -- he isn't used to their weapons. He's brawled with his fists and wielded a rapier (as was common for nobles at the time) but the robes are heavy on shoulders used to thin cottons and the bracers awkward and clumsy on his wrists. The flick of the hidden blade is foreign, and he has no-one to teach him the proper use until he is taken in by Mario. The heavy swords and maces and spears require so much force, and Ezio has always been a quick, lithe sort of fighter, filled with trickery and mischief instead of bludgeoning trauma

He does not know the right exercises to soothe strained muscles. Does not know what cramping to expect, and he is not used to running and leaping and diving in cumbersome robes and a hood that obscures his vision

Of course he is in pain. Of course he aches and cramps and curls up in a ball where nobody can see him as he tries to will away the persistent hurt. His body wasn't trained for this. Wasn't made for this. But he is forced to adapt anyway, and change everything about himself from the inside out. Would you not suffer from that too