My PRs will never garner attention or generate awards. But when I run, I am 100 percent me--my strengths and weaknesses play out like a cracked-open diary, my emotions often as raw as the chafing from my jog bra. In my ultimate moments of vulnerability, I am twice the woman I was when I thought I was meant to look pretty on the sidelines. Sweaty and smiling, breathless and beautiful: Running helps us all shine. A lesson worth passing along. [Kristin Armstrong]