I wonder, if the physical preparation aspect to playing an instrument is so important, then how do you get people like Yehudi Menuhin playing the violin incredibly fast at age three or four?
I believe the physical aspect of playing the piano is not of force or strength or speed. I think speed comes from coordination and MENTAL speed, not physical. Coordination is almost purely mental. The physical aspect of pushing down a piano key is nothing, you need about 30 grams of weight to push down a piano key. Physical exahustion comes from unnecesary tension (even if it IS a tiny amount). So, if you hcave the strength of mind to able to play witth absolutely no tension, and the mental speed and coordination, theoretically, you should be able to play the piano, even if you didnt spend 15 years developing your technique. Hense, you have people like Saint Saens (being able to play the 32 Beethoven sonatas at age 7), Mozart, Menuhin, Kissin, Hoffman, or countless others.