A triathlon is one of the most brutal and taxing sports that you can take part in. However finishing a triathlon can also be one of the most rewarding things that you can do in a lifetime. The worst thing that you can do is signing up to compete in a triathlon without training properly. Many people think that if they are a good athlete and they are in good shape, then they can compete in and finish a triathlon without too much trouble. This is not true.