By now, you should be totally comfortable with how the HIIT, Tabata, and core circuits work. Don't let your familiarity become a means for complacency, though! You need to attack them with as much energy as you can, every single day.
- Ab-wheel roll-out
- Medicine-ball twist
- Bird dog extension
- Reverse crunch
Option 1 HIIT
30 seconds work/30 seconds rest for 12 sets, or 1 minute work/1 minute rest for 6 sets
Option 2 Tabata
20 seconds work/10 seconds rest for 8 sets
Once you've completed your cardio workout, you'll move on to the following abdominal circuit workout. Together, these exercises will engage your abdominals, obliques, and lower back.
If you get tired of using this circuit, then feel free to replace some or all of the exercises with the alternatives.