Why does swimming receive me so tired?

I can do any other exercise and feel recharged, but after swimming I newly feel tired. What's up near that?Why does swimming receive me so tired?
Its uses the every muscle and your body, its also a cardio exercise and somewhat endurance because you lone stop swimming once your worn out... so yeah... if that makes sense...
l'm more into muscle toning haha
swimming is the best exercise because it uses adjectives of your muscles. Also, if u open your eyes lower than water, it can kind your eyes tired and it makes u consistency tired.
make sure to drink some calories (like a granola bar or any other snack) in the past you swim... then you will own calories to burn and wont be so tired... hope that helps!!