Why does the teacher always catches us when we are having less energy because it’s not fair?

The teachers also catches us when we have sufficient energy. But the reason she catches us all the time (if you have full energy or less energy) is when she saw us she comes to catch us, so we should we aware of her.

If she have seen you and come chasing you incase you have full energy it's your luck that you can run as fast as you can, But if she chased you when you have less energy you can't run faster......