Doing Sport With Underactive Thyroid How To Be Less Tired When Doing Sport ?

How to be less tired when doing sport ? - doing sport with underactive thyroid

When I swim, it's very tiring. I swim 3 times per week for 3 years and I'm really tired, what can I do? It's annoying, because everything else was easy. BTW, I'm not fat I'm thin, but I have some muscles. Also some tips on how to do this, eat and drink before you swim, could help? I am 15 years old.