SETTING THE TIMER (we recommend the Tabata Timer and HIIT Timer App which is free - search Tabata Timer in the App Store):

Setting up the app for this workout:
-Click the settings icon (lower right hand corner)
-Set "Initial Countdown" to 10 seconds
-Set "Exercise Interval" to 1 minute
-Set "Rest Interval" to 0 seconds
-Set "Number of Sets" to 9
-All other metrics can be set to zero

*the above timer works for each set of exercises (1 - 4). When you are done with 3 rounds of each set, reset the timer and repeat with round 2, 3 and 4.
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WARM-UP:
3 rounds: 10 reverse lunges, 20 total plank shoulder tap, 10 squat jumps

WORKOUT:
(3 rounds through each set of exercises)

1.
3 ROUNDS through:
1 minute side plank thread the needle (R)
1 minute side plank thread the needle (L)
1 minute to complete 80 high knees; rest remainder of minute

2.
3 ROUNDS through:
1 minute one-leg bridge lift (R)
1 minute one-leg bridge lift (L)
1 minute to complete 15 burpees; rest remainder of minute

3.
3 ROUNDS through:
1 minute single-leg V ups
1 minute mountain climbers
1 minute to complete 30 tuck jumps; rest remainder of minute

4.
3 ROUNDS through:
1 minute superman
1 minute tibetan roll + glute kick
1 minute to complete 20 push-ups; rest remainder of minute

X FACTOR:
3 rounds: 30 second flutter kick + 30 second plank hip taps

COOL DOWN:
Stretch legs (figure four, wide-legged forward fold, quad stretch) and arms (right and left arm across your body, tricep stretch)