( CNN ) -- Before I applied for the CNN Fit Nation program , I thought I knew quite a bit about the sport of triathlon . I had volunteered at a few races , helping athletes navigate the courses , and I even witnessed newly crowned world champions crossing the finish line . But what I knew , or thought I knew , was from the perspective of an outsider and very superficial . I really had no idea about the training that these athletes had gone through to prepare for their races . As with most things in life , seeing and doing are two very different things . I 've already written about my struggles with running , so you know that worried me from the beginning . But I 've changed as an athlete . The aches and pains are mostly gone now , and as long as I beat the heat and fuel my body , my running workouts are amazing . I 've learned to listen to my body throughout the day -- especially during and after a workout -- and my successes have surprised me . Follow the CNN `` 6-Pack '' with this interactive . Information is a powerful thing , and what I 've learned from my coaches and what I 've learned about myself has turned even me into a runner . I think many of my past problems resulted from trying to go too fast , too soon . In the past , when I started to see success , I wanted more , and that usually led to injury derailing my progress . I 've learned how to build my base endurance slowly and teach my body how to train with a slow and steady progression . I 've learned that you should never increase your distance more than 10 % per week so that your body has time to adjust to the increased workload . I 've been cycling for a few years , and I thought that would be my strongest discipline . However , I learned more about cycling at our May training camp in Florida than I thought possible . I learned the basics of riding in a `` paceline '' with my teammates and coaches , how to better control my bike and about the importance of keeping the pedals turning even when coasting ( the `` soft pedal '' ) . Who knew that central Florida was such a hilly place ? I learned quickly . After climbing some of those never-ending hills , I 'm a better climber and a better cyclist . Behind the scenes : Training for a triathlon . And that leads me to the pool . Swimming has become my nemesis -- and my biggest area of opportunity . Before starting this journey , I thought I could swim . I was wrong ! My first attempts at swimming in a lap pool looked like I was `` fighting the water , '' to paraphrase my coach . It 's much harder to swim when you 're trying to keep your head out of the water the entire time . The freestyle stroke , the breathing and everything else about swimming was completely foreign to me . As with the other disciplines , I 've learned to swim with the guidance of my coach and through lots of trial and error . Constantly practicing the exhale under water while only putting my face in the water or `` bobbing '' at the deep end of the pool has taught me how to control my breathing better . For me , the key to swimming was learning to relax . Now that I can better control my breathing , my workouts have finally become aerobic activities . To make my personal journey even more exciting , my girlfriend and a few of my closest friends have committed to taking a similar journey with me . They have started training and will be there in Malibu , California , not just cheering me on but racing their first triathlons as well . Now I 'm able to share what I 've learned with those closest to me . I often pass on simple tips , such as `` slow down and focus on your form . '' There 's no hurry when you 're training ; I 've learned that once my form is good , I 'm much more efficient when I pick up the pace . 10 ways to act like a champion . When I look back at the guy who first submitted an iReport to CNN , I thought I knew a bit about triathlons . But really I had no idea . The training once foreign to me is now a major part of my daily life , and I 'm excited to say it 's become a part of the lives of many people around me as well . I 've grown as an athlete and as a person , and I 'm learning how to train my mind as well as my body . When I cross the finish line in Malibu , I 'll cross with my teammates , my family and my friends . We will have all shared a similar journey , and we will all become triathletes together . Follow Mantooth on Twitter @ TriHardStacy and Facebook .
Stacy Mantooth was an avid fan of the sport of running before joining CNN 's Fit Nation . He 's training for his first marathon and has learned a lot about the do 's and don'ts . He is sharing his experiences with family and friends who are training with him .