Nipple Chafing

I'm a fan of body glide.

Lube em up and let it roll.  I've had no problems even wearing a regular cotton t-shirt for as much as 16 miles (so far).

Amputation.

Short and to the point - hahahahahahahahahahahahahahahahahahaha!!!!!!

Smarmy answer - Don't run.

Some suggestions:
1). Body Glide - it works when aptly/generously applied.
2). Band-aids over the nipples to suppress the rubbing of nipples directly onto the fabric.  Just watch when trying to pull the Band-aids off afterwards.
3). Depending on the material, sometimes cotton is not your friend.

I didn't find body glide to be effective.

I did find the small round band-aids to be.

I also stopped wearing the cheap 'tech' shirts they give away at races. I save those for yard work.

Tape.  Medical tape.  The second stickiest that you can find.  NOT THE STICKIEST!

Tight shirts like underarmor, or desoto coolershirt work for me. If the shirt is even a little lose, I'll be chaffed. If it's cool out I'll wear a second shirt over top.

I'm one of the people BodyGlide doesn't work for. I'd also be surprised if it works through an entire IM without reapplying.

2Toms SportShield Roll-on, on the other hand, works for EVERYTHING (works much better if you apply it) and stays strong through marathon swims and IMs. Still slidey at the end, but easy to get off with soap and water.

I get nipple chafe even with a firm sports bra and tight top. 2Toms is my friend!

I'm a man - doing marathon in January and been doing longer runs than I normally do. I cover them in vaseline or body glide. Works fine. I have never used tape/ or bandaids. Having a good shirt matters too. Can't speak for ladies of course.

^^^^This.

You can do the body glide and bandaids, but you should make your nipples tougher.

I reccomend starting with say a 600 grit sandpaper for about 60 seconds to 120 seconds at least once daily, and each week decrease the grit of the sandpaper by about 50.  By the time you reach 100 grit or less, you wont have any nipple issues, I promise. 

Besides that, you can make sure you are hydrating properly.  When your sweat dries, it can leave salt crystals that do rub like sandpaper.  Wearing sweat wicking shirts help as well.

Sadly all that doesn't do any good because nipples are one of two places that skin doesn't toughen.  You don't want to chafe the other one, either. ;-)

I go with the CVS/Walgreens spot bandages.  100 for $4 and zero chance of nipple issues.