shrug Metabolic damage is a real problem in the bodybuilding community. I don't have any stock in the exact numbers being there; 800 calories and 3 hours of cardio per day is not much worse than 1200 calories and 1 hour of cardio per day. Both indicate a depressed metabolism and an inefficient (if not counterproductive) weight management strategy.

I'd agree that 800 calories and 3 hours of cardio per day and constant weight is extremely unlikely hypothesis vs. misrepresenting food intake or activity level. I don't think it's impossible that a person can adapt themselves to that. Some coaches prescribe this caloric intake and activity level.

To see how plausible it was, I hypothesized a 25 year old 5'2" 120lb female aspiring bodybuilder at around 11%BF. This RMR calculator puts the basic metabolism at 1,200-1,500 calories per day. 2-3 hours of low impact aerobics gives 662-993 calories according to this calculator. Assuming cardio is done 5 times per week, this is an average of either 1,670-1,972(2 hours cardio) or 1,900-2,200 (3 hours cardio) calories calculated to maintain weight.

The most extreme situation (2,200 calorie maintenance and 800 calories eaten = 1,400 calorie deficit) seems obviously impossible. The other bound (1,670 calorie - 800 calories eating = 870 calorie deficit) seems more possible to me. I've personally had my maintenance calorie intake down to about 1,500 (and i was meticulously measuring everything), which is ~700 calories less than calculators would have predicted given my activity level.

And they under-reported significantly.

Not surprised. Virtually everyone underreports (unless they're chronically underweight, and then they overreport). That's why I included the bit about Layne's personal success (ie what he does really works for himself) and coaching success (ie what he says works for his clients). He practices what he preaches, and his results speak for his methods.