Rabbit Blur
A rabbit blur occurs when two (or more) very fit, strong, and healthy individuals have sex and everything becomes a blur. While a rabbit blur is occurring the rhythm of the two individuals becomes as one so they do not have to think anymore, They can simply concentrate on providing such awesome and unspeakable pleasure.
Person A: "Wow, Me and that chick were sexing it up so fast and for hours last night. She was bouncing so fast she became a blur"

Person B: That's rabbit blur sex. I'm fat and lazy now, just can't get that speed going for that long anymore.