You will need a timer for this one!

Time the first exercise in your Combo (ie, 50 x Mountain Climbers).  You will then drop to a plank for the equivalent amount of time.

Repeat the Mountain Climbers for 100 reps, then drop to a plank for the same amount of time. Repeat for all reps in all combos!

Combo #1 : Mountain Climber VS Plank :  Round 1 x 50    Round 2 x 100   Round 3 x 150

Combo #2:  Chest to Floor Burpee VS Wall Sit:   Round 1 x 10   Round 2 x 20   Round 3 x 30

Combo #3:  Push up VS Pulsing Pushup:    Round 1 x 10   Round 2 x 20   Round 3 x 30

Have fun!