Laura was a self-certified couch potato who, until a few years ago, could only run for a couple of minutes at a time, and couldn't swim. She has now completed several marathons and is a committed triathlete. But Laura couldn't have achieved what she has without the advice and support of her friend Katie. A life-long runner, fair-weather cyclist and born-again swimmer, Katie helped Laura through the ups and downs of training for a triathlon. As...