"Quick Jumps"

[Zen]

Quick jumps will get your heart rate up/improve cardio ability and burn more calories but will also use up the glycogen stored in the muscle. You'll be pooped for the rest of the class.
I don't do them either.

[indysteel]

Some of my spinning instructors do these, too. They typically refer to them as jumps. I rarely do them. Regardless of whether they relate to anything I actually do while riding, they just bother my knees a bit too much.