I can only manage to get through one 30 minute HiiT, or I swear, I'd have an asthma attack and die ;-) So I do Pyramid. My GF is made of much tougher stuff than me, so adds on 40/20. I honestly don't know how she does it!! I do a Cathe Cardio (the one with the stability ball) for another 20 minutes and call it a day.