CFC

For time:
80 DB box step-ups (20/24 in) (35/50 lb)
– Every minute on the minute, starting at :00, perform 20 double-unders.
– Use two dumbbells.

PureFit

For time:
80 DB box step-ups
– Every minute on the minute, starting at :00, perform 20 single-unders.
– Use two dumbbells.