Since I started running regularly earlier this year, I've picked up a lot of first-hand knowledge. Not all of it is pleasant, however.
This would fall into the unpleasant category.
One side effect I have to endure after most of my runs is pain. It's not chronic pain, such as back or ankle pain. It's not mental pain or any sort of emotional anguish.
Nope. It's my nipples, possibly the most useless part of my body. Really, what purpose do they serve me? Actually, before this unpleasant side effect, I don't think they ever had any sort of feeling or anything. I'd never called them into action per se. They were just there.
And now, they are a lingering side effect of my runs. Typically after a run, my nipples hurt. They're tender and quite raw. On more than a few occasions, they actually have bled. In fact, once I wore a white t-shirt to the gym and did I believe a 42-minute interval run - either that or a 4-mile run. Anyway, when I was done with it, I was about to step off the treadmill when I noticed something on my chest. I hadn't been able to see it during my actual run but after I'd stopped and shifted my body around, I saw a streak of red down the left side of my chest. It looked as if I were lactating blood. I covered up and went straight to the bathroom.
I've done a little research into it. You can get this condition apparently because your shirt repeatedly rubs against the nipple during prolonged running. Makes sense too. If you run for 40 minutes, a shirt could really rub you raw.
Some of the ways to treat it are to run shirtless, wear tape or band-aid or something, and to rub vaseline on it before a run. I don't run shirtless and probably won't anytime soon but I tried the band-aid once. After a run, though, my nipple hurt and when I checked for the band-aid, it was gone. There was absolutely no sign of it anywhere.
My last option is the vaseline. I've not tried it but after my last couple of runs resulted in some lingering pain I decided that I need to do something about it. So far, though, that hasn't resulted in an actual purchase of vaseline or anything of the nature. Hopefully it works. It's not that the pain is intolerable or even long-lasting. It's just an uncomfortable side effect that, if I can avoid, would be good to do so.