i understand what you are saying and i agree with you. absolutely the long season causes wear and tear. no doubt that many, many MLB players are very much "athletic". my point in defending Moons original point was that of the 4 major sports...you can last in MLB in less than stellar physical shape. the other 3 sports will not "allow" that.
NBA: average player is 6' 7'' tall, weights 218 lbs and is 26.9 years old.
NFL: average age 26
NHL: 26
MLB: 29
The average playing career for an NFL players is 3.5 years, the average MLB career is 5.6 years, the average NBA career is 4.8 years, and the average NHL career is 5.5 years.