I run/walk most everyday's up to almost 8 mile's some day's, i really really enjoy my time outside, But when i get home OMG i'm starving i could eat & eat for the rest of the day. Good thing i count point's (ww). Today i knew it was going to rain at somepoint so i rode my bike instead for the same amount of time and my guess for mile's would be about 27 mile's and i was fine when i got home,or should i say i was not a bear who had not ate all winter.

I don't actually get this feeling after long runs (thank goodness), but it is common for people to be hungry on long run days. It is why some people find themselves gaining weight during marathon training, even though they are running such tremendous mileage.

It is interesting that you don't feel the same thing after a good long ride, not sure why. Maybe your body is releasing different chemicals based on different exertion levels. It's a mystery!