I grew up in competitive swimming and my father was an all American at Stanford. I can say with 100% confidence that the training involved for the majority of events in swimming is far more time consuming, and generally tougher than distance running. It can be completely miserable sometimes during the heaviest phases of training. I would also say you're average collegiate swimmer has a much higher pain tolerance than your average collegiate runner. I've seen both sides, and the only reason I quit swimming was because I had much more potential in running. I was working hard for little in return while swimming.
Before someone responds questioning my running experience, yes I have run faster and competed at a higher level than the majority of you on this board. No, I will not expose my identity to the LRC board. Many of you are going to be pissed that I have just states some well known facts. Swimming is more appealing, and popular to many Americans. Unfortunately the body type that is necessary to running successfully is not physically appealing to American women. And thank God you don't have to read about male swimmers becoming anorexic.
PS refer to the strokes as back, breast, fly, and free. You'll appear somewhat more knowledgable about swimming the next time someone mentions the olympics in the office.