It compared how fast you run and tells you what you can outrun...

That sounds like something from theoatmeal.com. He does things like, "How long could you survive after kicking a bear in the balls?" and, "How many Justin Biebers could you take in a fight?"

Thanks @catfluff! That was the one I was looking for...
And @jasonmon thx , sounds interesting, I’ll take a look...

You never know when you'll need to know important things like how to tell if your cat is plotting to kill you. I like the website @catfluff linked to, though. I need to try it out later and see what ridiculous animal I can outrun.

Happy to help :-)