Annie (CrossFit benchmark workout)
50-40-30-20-10 double-unders and sit-ups, for time.
Named after CrossFit pioneer Annie Sakamoto, this is a coordination test dressed up as a sprint. If your double-unders are reliable the sit-ups become the limiting factor; if they are not, tripping on the rope decides everything. That makes Annie a useful skill check as much as a conditioning one.
CrossFit puts Rx finishes at seven to eight minutes and advises keeping it under 12. Athletes still learning the double-under can do the intermediate 30-25-20-15-10 scheme or the beginner version with single-unders, rather than spending the workout restarting the rope.
More about Annie (CrossFit benchmark workout)