( CNN ) -- A little more than two months ago , I stood on a California beach , tears streaming down my cheeks as I watched members of the 2012 CNN Fit Nation team cross the finish line of the Nautica Malibu Triathlon . A year before they had never worn a pair of running shoes , let alone a triathlon suit . For many of them completing a triathlon was utterly inconceivable , akin to asking them to walk on the moon . But what a difference a year made . At the Nautica Malibu Triathlon , I saw the Lucky Seven athletes conquer their fears and achieve more than they could have ever imagined . Their courage , strength , happiness , elation and pride were a beacon that shone for all to see , and that light continues to inspire everyone who shared in their amazing journey . It was an absolute privilege to join Dr. Sanjay Gupta and Coach April as a guest coach for the 2012 CNN Fit Nation team . The finish line was not the end for the Lucky Seven ; it was just the beginning . Their journey did not simply bring newfound physical fitness and vigor . The experience gave the team members altered perspective , a sense of purpose , healthy eating habits , a wealth of new skills , mental fortitude and a string of wonderful memories . It gave them a new life as triathletes , filled with belief in themselves and lifelong friendships . Of course , challenges are never easy . It takes a huge amount of courage to try a new sport and set a new goal . The Lucky Seven all had personal barriers . They were all nervous about testing themselves , taking risks and biting off more than they could chew . They all worried about the what ifs . What if I ca n't do the training ? What if I ca n't learn to swim ? What if I crash on the bike ? What if I ca n't finish ? What if I let myself down ? While watching them conquer their fears , I realized once again that the only limits are those that exist in the mind . The key is to overcome and move beyond them -- to a space where our real power dwells . Ironman champ : Train your brain , then your body . Four years ago I was asked whether I would ever do an Ironman . My response ? `` No way , you must be completely mad to do something like that ! '' But once I had done the shorter distance races , I realized that maybe the Ironman mountain was n't so big after all . I gained confidence in myself , and with the support of my coach and training partners , I seized this new , exciting challenge with both hands . Imagine if I had never gone back on my word , if I had n't changed `` I ca n't '' to `` I can . '' Imagine if I had n't dared to push myself harder , and most importantly , if I had n't had people to support , encourage , mentor and make me believe in me ? I would never be sitting here as four-time Ironman World champion . Getting to the starting line of your first triathlon . The same goes for the 2012 CNN Fit Nation Team . If the team members had n't had the courage to overcome their fears and doubts , they may never have been able to call themselves triathletes . And they , and their families and loved ones , may not be looking to the future filled with optimism , positivity and unbridled confidence . I await the news of the selection of the 2013 CNN Fit Nation team , knowing it marks the start of a journey that will change lives , empowering a new group to defy what they may have deemed impossible and inspire everyone else out there to do the same . This is the start of a new beginning , for them and for you . To apply to be a 2013 CNN Fit Nation team member , go to iReport.com and share your story . If you are selected , you 'll receive a bike , uniform , wet suit , personal training and nutrition coaching , two all-expenses-paid training trips and a chance to train and compete alongside Gupta at the 2013 Nautica Malibu Triathlon .
Apply to join the 2013 CNN Fit Nation Triathlon Challenge on iReport.com . TL;DR The average American woman weighs in at about 150 pounds and is considered obese. The only limits are those that exist in the mind , she says .