The answer is both are good for you and that your training should consist of slow long runs, tempo runs and speed/hill sessions.

I don't know if either long slow or short quick runs burn off more calories...I suspect that the calorie loss is the same if the effort put in to each type of run is equivalent....if you get what I mean.

I wouldn't be surprised if someone gets back to you with a scientific answer/website that may assist and it would be interesting to see what, if any, research has been done on the point.

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