Men Nipples Bleeding

I recently helped at the ing nyc marathon 06 and notice many of the male runners where bleeding. I asked several of my male friends and family members and none of them knew. Why and How do men nipples bleed?

Thanks

[Jules_za]

new shirt and friction?

[lhowell]

I agreee with Jules...when my father-in-law ran marathons, he had to put band-aids over his nipples to keep his shirt from rubbing the skin off the nipples.

[Fred's Dad]

Bingo!  You figured it out!

26.2 Miles of running with fabric rubbing up against a man's nipples will indeed rub the nipples raw and cause the bleeding.  I am a triathlete,endurance cyclist (100 plus mile events) and marathoner.  Band Aides over the nipples prevent the rubbing or chaffing.  I never leave home without my band aides.  

[Ironheart]

A related discussion, nipples hurting/burning was started.

[Malhi]

A related discussion, Why do i experience pain, sensitivity and bleeding sometimes from my nipples after a hard cardio workout? was started.