Interested in Triathlon?.
Here is an interesting blog . http://mangolds.blogspot.com/

Being Triathlete and competing in Ironman contests is very tough. Imagine swimming 2.4 miles, biking 110 miles and then run for 26 miles. I would be extremely content if i did any of the three , forget doing all of them together.

So much for my fitness. It is no comparison with what some of these Athletes do.