I'm starting week six of the twenty week course tomorrow. I use 1.5 wrist weights, I added them in week 3. They add intensity, and also if I'm beat at the end of a workout in can take off the weights and it feels way easier so I can power through. I add HIIT 15 to my core 20/stretch 40 day, because getting my heart rate up is important and the core work keeps it up. I usually burn around 600 to 800 calories combining all the days classes (like maybe fire 45 ill burn 650 then another 130 for stretch 10).

I'm a nurse and I'm against most supplements. I've considered shakeology but am not using it. I also didn't do the inferno, but if you aren't very fit you should consider doing the prep schedule and not starting with inferno, it might burn you out right from the off. Good luck!