Lance Armstrong was close to tears when he spoke about his having to tell his son not to defend him.
He said: "When this all really started I saw my son defending me and saying 'what you are saying about my dad is not true'. And almost goes to this question of why now.
"That's when I knew I had to tell him. And he had never asked me, he had never said 'dad is this true?' He trusted me.
"At that time I didn't say something, but I knew I had to."