I have a couple of eggs that I've picked up from some Pokestops (I'm lucky enough to live above one).
I walk a lot. I get to work through a 2 mile walk / train journey every day, so I should be picking up loads of steps for the eggs I have. However, because I'm normally always running late... for everything, I have to rush everywhere, so I walk at an above average pace.
Today I've walked around 5 miles, but the game has registered 100 metres. Is this because I walk too fast, or because of something else?
It's worth pointing out that I have the app open when walking... mostly because I have to catch them all. (This made me miss a train this morning... luckily I was early :D)