Endurance WOD Workout

In teams of 2 share the reps and complete as many rounds as possible in 40 minutes:
40 Calorie row, 40 Med ball Sit-Ups
40 Calorie ski, 40 Med ball Thrusters
40 Calorie row, 40 Med ball russian twists
40 Calorie ski, 40 ball slams

One works, one rests.