The cyclist last month gave up his appeal against long-standing doping allegations, resulting in the US Anti-Doping Agency invalidating his performances in all professional races since August 1998 and handing him a lifetime ban. Armstrong has continued to protest his innocence.
Speaking on ABC talk show Katie yesterday (September 10), Crow described Armstrong - who she dated between 2003 and 2006 - as "someone I really care about".
"I know how hard he worked to win those titles and it was hard to watch," she said. "I felt bad for him, I felt bad for his family.
"He's a hero that we've watched for a long time and admired... He's probably tired of the whole fight."
It has been reported that Crow was questioned during a probe into Armstrong's alleged doping last year.