Yesterday when I was flying a multi practicing Vmc and stuff, I noticed that my fingers began to hurt. I found relief by holding the wheel with both hands and released pressure from my left hand. This has happened to me before when I fly but it pretty much goes away when I go into cruise or just stop doing maneuvers. This is probably just muscle strain or something but does this happen to anyone else? do you recommend I start doing hand exercises like a stress ball or something? I do hold the wheel pretty tightly though.

This only happens when I fly so I doubt it is arthritis or something.
I'm 18.