It is not easy. I played a game called 'strikeout' growing up. Just a tennis ball, a bat, a wall and two people: pitcher and hitter. You got to throw/pitch and hit all day long. Many more throwing and hitting reps than the best run baseball practice. I was good enough to beat all the older guys but throwing full-out and throwing curves with that tennis ball took its toll. I had a great arm until it blew out. Like with all things there is balance and that is where a good coach comes into the picture. He/she has to know when to back off and let the kids play (and encourage them to go play and not just practice fundamentals). The folks on this site seem to understand that. I'm not so sure all the golf instructors do.