Well I tried that link, it didnt work, so Ican't comment on what they say at all. As for natural legs, this isn't always true- genetics, (along with other things) will determine how fast you grow and to what ultimate size, but anyone can improve. I started out with 22 " thighs and they are now 29- even though I am cutting up right now. They only grew to 25" my first few years of training and it wsn't until I did HEAVY leg work that they grew- by heavy I, mean squats up to 500 or 600 lbs , leg presses over 1000, and pegging the stack on the leg extension machine. And none of that 4 or 5 sets of 10 crap either....warmup, do your heavy set or two, then move on, then go home and rest. My legs grew best on once or twice a week workouts..I presently do them once.