eli5 why is exercise supposed to make you tired if atp is not stored?

Question

I read that atp is produced constantly as needed and that you can only store about a minutes worth, so how is exercise supposed to make you tired and sleepy if you’re not using up your energy?

In: 19

Answer 1

Your muscles tear down when you excessive and are repaired. Kind of like if they were Lego sets how easy it is to knock down a Lego castle but it takes more time and energy to rebuild.