You can train yourself to do anything if you all willing to work on it on a consistent basis!

It's not really genetics, however athleticism does play a role. can a 23 year old non athlete, 40 lbs over weight, book worm train to throw 90 mph, probably not. but if you are somewhat athletic it is entirely possible. 23 is not too old. Too gain a pitcher's arm, all you must do is throw.

The muscles in your arm are like any other in your body, they grow stronger with exercise. so throw often. Start out tossing gently, maybe 40-50 tosses a day at 60 feet, and then build up each week (as long as there is no pain). eventually the best way to gain arm speed is to throw "long toss". long toss is a 15-20 minute throwing program that lengthens the muscles in the arm and allows pitchers to throw harder. start out at 90 feet and throw until you are fully warmed up, then move back 15 feet at a time, at each distance make 15-20 throws. keep moving back until you reach 180 feet. when you throw, make sure you concentrate on keeping your arm motion long, think: keep my hand as far away from my shoulder as possible when releasing the ball. when you have reached 180 feet, move in 30 feet at a time, make 10 throws at each distance and try to throw the ball on a direct line at eye level to your partner.

What does pitchers arm mean? Anyone can pitch, but can they pitch 94mph with movement? No, you need to be born with that type of talent. I use to pitch when I was younger and I could never throw like that.