Just found this on the web:
"Many people observe that they feel like 'eating a horse' after they have finished a swim training session, and may overcompensate for the energy they have just burned," says Professor Louise Burke, Head of Nutrition at the Australian Institute of Sport.
They reckon that the temperature might have something to do with it, that running or exercising another way causes you to feel hotter and possibly supresses your appetite.
Anybody experience this? And more to the point, might be a great way to feel hungrier and stuff more food into the system once in a while.