But the great thing about them is that they make you super active and they burn through calories (3500 calories per lb of fat) like CRAAAAAAAZZZZY!
So doing things that give you an adrenaline high can help you lose more weight in a hurry.
However HOW you find ways to get an adrenaline high is really up to the individual. So what I want you to do is to think of a list of things that get you really excited - and possibly even scared - and eliminate any from the list that might end in bodily dismemberment, death, etc. What remains can be used to help you exercise - and run faster than you normally would.
Sometimes you only even need to simulate or pretend that the thing is happening. Children do this all time while playing, pretending to be running from explosions, flowing lava, etc. (Adults even do the equivalent for fun sometimes, things like LARPing, Paint Ball Warfare and even contests like Tough Mudder. Something for everyone.)
The last one below is my personal favourite. :)