Quoting this from the cyclingnews forum. These are the guys who have known pretty much about every single detail that was written in the USADA reasoned decision, long before it was published. Quote:
"Hmmm, I wouldn't be so sure his marathon results were PED free, because in the emails between Armstrong and Ferraris son Stefano he is discussing how he wants to meet "schumi" so he can run sub 2:50."
Remark: Ferrari is the Italian doctor Armstrong was working with but then "stopped", only to continue to work with him through Ferraris son. A straw man.
I know, 2:46 is nothing to write home about but it seems possible that he didn't even have the natural talent for it.
Also, folks over there are suggesting his doping started during triathlons in the late 80's/early 90's since his coach back then was a TEAM USA Olympic coach from 1984 that was later found to have administered blood doping.