Armitsead was unable to find her best form and finished fifth, following a week of turmoil during which she was given an Olympics reprieve by the Court of Arbitration for Sport after missing three drugs tests during 2015.
London 2012 silver medallist Armitsead, 27, was in contention until the final stages when she fell away as Dutch rider Anna van der Breggen claimed gold ahead of Sweden’s Emma Johansson and Elisa Longo Borghini of Italy.
“I can’t feel sorry for myself,” said Armitstead. “This is sport and that’s what it’s about. You open yourself up for judgement. I never gave up and for that I can be proud of myself.
“Obviously, I’ve lost quite a lot of sleep and it’s been a hard time, but it’s not an excuse. Once I’ve got a number on my back I’m a totally different person and I’m focused and it didn’t enter my mind once in the race. I was totally focused on what I do best.”
The event was marred by a serious-looking accident involving Van der Breggen’s team-mate and then race leader Annemiek van Vleuten, who suffered a dramatic crash with only 11km to go. The Dutch federation later confirmed that Van Vleuten was conscious and had been taken to hospital for further examination.