short term stress is could be like babysitting an annoying kid for 1 hour, you will be annoyed by said kid and when your hour is up and your golden
Long term stress is like babysitting the same kid but for every day for 3 hours an day 24/7 that stress builds up and you kill the kid
We get tired after exercise because our muscle fibers get tired very quickly. This is due to the major source of energy for the muscle tissue, called adenosine triphosphate, or ATP. As the muscles make use of this supply of energy, they get tired and fatigue.