Whilst I have no enthusiasm to look up how to work out what you should have burnt up, I find the claim you would have burnt up 665 calories in 45 minutes rather far fetched. When I did check out how much one needs to do to burn off a few calories, many years back now, I decided that sporodic exercise had little effect re weight loss. It's possible it may do more than I figure, but the rate you say sounds way over the top to me.