http://www.digitaljournal.com/article/57457

Marathon runners may face greater skin cancer risk

Posted Nov 20, 2006 by KeithLDick

http://today.reuters.com/news/articlenews.aspx?type=healthNews&storyID=2006-11-20T214640Z_01_N20462991_RTRUKOC_0_US-MARATHON.xml&WTmodLoc=Home-C5-healthNews-3

Interesting... I can see the part about them being in the Sun most of the time and I would have assumed they used Sun Tan Lotion, I guess not...
The marathon runners were found to have more atypical moles -- larger than common moles, with irregular and poorly defined borders. They also had and more so-called liver spots -- small, flat, brownish harmless lesions also known as solar lentigines.