This is with regards to the olympic style dope test.
So this substance is untraceable thru urine tests, hence the need for a blood test. AND this substance flushes off your system very quickly, that a blood test is needed very close to the fight.
From what i know, HGH doesn't exactly provide any athletic advantage. Steroids can be traced from urine.
So which one exactly is it MAnny is "on"?
I don't think he's on anything, but if he is, it could be EPO.
EPO to my understanding is a relatively short acting Performance Enhancing Drug.
EDIT
Here's some links on EPO
http://www.sportsscientists.com/2007/11/effect-of-epo-on-performance-who.html
http://www.bikeforums.net/showthread.php?566541-How-does-EPO-Work
Its out of your body in a couple of days, but the effects lasts for weeks.