I love to swim, I go to the lake all the time when I can, Do you know anything about swimming? 
It's a rather low-impact exercise activity compared to running or lifting weights, and it's used often in physical rehab because of that.
Oh yes I have heard of that, Doesnt swimming give you more excersize though? How many calories do you burn?
It is great exercise, and it's quite a popular recreational activity too. Generally if you swim for an hour (not just leisurely but seriously) you can burn about 600 calories.
That is a lot wow, Ive been wanting to get into competitive swimming, How fast do Olympic swimmers go anyways? 
In international competitions and the Olympics, you can expect the average pro swimmer to swim about 5.3 mph, which is pretty fast in water!
Wow thats impressive, most people cant even run that fast lol. Any other cool swimming facts I should know? 
You might have heard this before, but you can hold your breath and sort of swim at a basic level within weeks of being born. It's part of human evolution.
Wow really? thats wild! maybe humans were meant to be born in water? fascinating! 
Even if we weren't, we seem pretty well suited to play in it at least, which is great considering 75% of the planet is water!