Muna Lee qualified for Beijing in the 100m and 200m at the US Olympic Trials, the only runner to do so. This was particularly impressive given that she'd had a period of injuries for the years prior. This is her take on her renewed confidence.
"My coach told me that he believed in me. When he told me that, I began believing it."
Social persuasion is one of the four ways in which a person increases their self-efficacy. Someone you respect tells you they believe in you, and your confidence increases as a result. It's uncanny how often it plays a role in helping a struggling athlete overcome that adversity and begin to excel again.