*sighs*
Right...
Swimming stuff...

The human body only has a certain amount of blood. You don't need lot of it in lots of places, at the same time.

When you're being active, there's an increased bloodflow to the lungs and big muscles that you're using.

This means that the "extra blood" has to come from elsewhere. This means that there's reduced bloodflow to the digestive tract, amongst other places.

Ok...

So, if you eat a big meal your body needs to do several things with the food.
The tube-pipes like the throat and intestines move food with muscles, and the stomach is a big bag of muscle that mashes food up.
These muscles need an increased bloodflow to digest food well.

So, the point I'm making is that you can't do hard physical exercise at the same time as digesting food.

You can go swimming, sure. The worst that'd happen is you get cramps. Maybe not awful craps, but cramps all the same.

Just don't go for a sprint after Christmas dinner.
You'll feel terrible, and likely throw up.


EDIT: I hate you all for making me think hard after a roast dinner.
( Cawl, Sun 21 Sep 2008, 20:54, Reply)