In the Ironman, the swimming portion is 2.4 miles, the biking portion is 112 miles, and the running portion is a full marathon, 26.2 miles. This is an intense and extremely challenging event which many participants do not finish.
The type of your body relies completely on genetics. You will notice that your body type is similar to your siblings or parents. Because your type is a genetic trait, it can be impossible, or at least quite difficult, to change.
To have the best results at losing stomach fat, you will need both aerobic exercise and strength training. To really get the fat moving, you want your cardio exercise to be at a really high intensity.