I'm not happy if I'm not doing some physical suffering, like going out on a bike ride or running. First, it's good for you. No. 2, it sort of clears my mind on a daily basis. And it's a job. My job is to suffer. I make the suffering in training hard so that the races are not full of suffering.
As quoted in "10 questions for Lance Armstrong" by Bill Saporito in TIME magazine (28 September 2003).