Your mind will want to stop working long before your body really needs to. The reserves that you possess physically to keep going are something that we really have to marvel at. If you disagree, I think there are plenty of examples of where the human body can keep going when the need is real, as long as we get our mind on board.
When a player tells me they are tired or, even more challenging, too tired to keep going I have to wonder if they even know what true physical exhaustion is. In most cases the answer is a resounding “no” because we never put them in a position where they really need to dig deep. We let them off the hook as soon as they appear to be getting tired so they don’t know what “tired” really is.
Softball is a sport that usually doesn’t require a player to dig deep because the game has plenty of pauses and breaks in the action. Where we usually see or hear about fatigue is when we stack up a bunch of games in a tournament or play a marathon game that goes way into extra innings.
The fact that there are so many chances to rest in a game is both a blessing and a curse. We don’t usually need to have that much endurance but because we don’t need it very often we don’t work hard enough on it.
Where the endurance becomes so valuable is more in a player being able to maintain their focus for a longer time because they don’t feel fatigued. It doesn’t take much for a player’s performance to suffer when a player feels tired. They’re much more likely to become distracted and play poorly.
When a player reaches a minimum level of fitness, they are on their way. When they become committed to it they will see real payoffs. As long as they understand that no matter how “tired” they are, they still have more gas in the tank.