How to avoid sore nipples while riding I have a recurrent problem when riding in high humidity climate, either with hot or cool weather: after some hours riding, my nipples (in the chest, not in the wheel :o) get very sore from friction against the shirt's fabric.

It seems that it has to do with salty sweat, the waving-flag movement of the shirt fabric against the skin, and perhaps with cold causing nipple erection, further increasing the friction.

A more experient friend of mine has reported the same recurring problem, having even seen people bleeding from this.

So I ask if anyone else has suffered from this problem, and how I could expect to solve it. I am considering to take along some band-aids, but I think there could be some preventive measure before the band-aids be needed, in the first place.

Thanks for any insight!
This happens to runners more than bikers but is the same thing you describe... friction. 

I've done band-aids, tape and even special products (Nipguards) made for covering just the nipple area but the best remedy I've found is compression clothing. Even in the middle of summer, I will wear some skin tight Under Armour shirt. Heat Gear (odd naming, but actually cools the skin too) in the summer just to prevent friction between cycling jersey and the nipples. I'll switch to their cold gear during the winter, but always wear something skin tight under my upper layers.