LeMond became embroiled in a 12-year legal feud with Armstrong, which he told Newstalk ZB's Tony Veitch today was "the worst time of my life".
"I got nervous for my own safety," the now 56-year-old Lemond said. "The blessing for me was when USADA took away his Tour de France titles. Everything, his power, was gone... he was obsessed with me so it was a good relief."
LeMond said he knew about Armstrong's involvement in performance enhancing drugs in 2000, but was prompted to speak out when he saw Chris Carmichael, Armstrong's coach, injecting steroids into a 17-year-old cyclist.
LeMond said the stress of being under Armstrong's attacks left him suffering from adrenal failure - for which he needed medication.
"I've had so much trauma in my life - I can survive a lot of stuff. I'm like a cockroach."
Famously, LeMond won two of his Tour de France titles after being hit by a shotgun blast fired by his brother in law when on a turkey shoot in 1987.
He still has lead pellets in his body. In 1989 he won on the final day of the Tour when overtaking rival Laurent Fignon in the time trial, a spectacular finish which brought aerodynamic cycles and equipment into the mainstream.