I do 360-400 bicycle crunches constantly in 6 minutes. How much calories do I burn?

If I had to guess, I’d say about 50, which is about 8 calories a minute.

360 crunches in 6 minutes is about 60 crunches per minute, which is one knee to elbow per second. That’s a nice steady pace that would put someone in a mid-range intensity level for cardio – more than a walk but less than a sprint.