According to lyle macdonald the body has a capacity of approx 500g carbs worth of glycogen (if memory serves). Thatd be 2000cals..
Also it takes approx 10-12 sets per muscle group to deplete glycogen and this is at 60% 1 rep max at 45-60 secs under tension. He also instructs u to do additional cardio "in case theres still some glycogen left over"..
I have done this depletion workout over a pd of months. I know it well. It is brutal and painful and the hardest workout ive had to do. NO WAY this can be duplicated ina 45 min spin class.. Or even 45mins of a tour de france race at tour de france speed..
It takes me about 1.5-2 hrs to complete per day amd its a 2 day process (3-4hrs)...
Mockery: my test was 900(total) 25(free) during the time of this cut i referred to above.. Within normal ranges..