As the others have said, I’ve always assumed it’s about cooling. In a marathon, even running “within yourself”, you still end up getting pretty hot even if the conditions are cool.
I don’t particularly like them however. There are a lot of drawbacks. The chafing under the arms (about 3 inches down from the armpit on the arm, and the same spot on the side of the torso) is horrible, and I have to body glide / vaseline up that area significantly. And then there’s the nipples. In any training I will ALWAYS wear a tight fitting base layer. Then you don’t have any problem. But run more than a 10k without some form of nipple protection and it’s a lot of pain for days after.
I now use these which are great. They actually stay there, unlike plasters, or vaseline which rubs away pretty quickly.
I never had problems with my nipples or underarms in the past, but since starting again, the nipples have been chafing. I tend to be okay for the most part, but some of the cheaper t-shirts from events are awful at rubbing the nipple head off.
Vaseline works for me, but tends to stain the tops, so only use on dark material.
Tend to find the inner thigh/groin area the worst, depending on the shorts.
But cycling chamois cream sorts this out.
I use plasters for nipples. Years ago I could wear just shorts on my legs but today that skin is weak and soft, so anything over 5-8km I wear some kind of undershort.
I think the skin chaffing with a vest would be an issue for me but I’m willing to try. I just thought it was odd that such a lot of frontal area is flapping around in the wind. Clearly I don’t run fast enough.
you need to buy better vests then. I used to suffer chaffing with my old club’s vests as they were old, scratchy and heavy. but i have a Saucony one and a carft one and they’re as light as a feather. I’ve never had a single bit of chafe from either of them. My new club vests aren’t the greatest, but they’ve not given me any grief so far.
Yeah the latest couple of batches haven’t been so good. i think the supplier has started taking some shortcuts as they’re much rougher than they used to be. I still find them fine though, and pretty much only wear them and the few other race shirts that i have.
I have thought this in the 100/200m races on the track though to be fair. surely at those speeds aero means something. Yet you always see chains flapping in their faces, and not everyone wears tight lycra suits (though more do now than previously).
I was going to say above, you do see it in the short distance track, where they are now often wearing one piece skinsuits like you would see a TTer wearing on the bike. But cooling matters little in such short events, and aero would be king.
The chains I agree with. And flappy hair, bandanas, whatever. In an Olympic final, when everything you have worked for is on the line, you’d think they’d shed every single item that is not directly attributable to improved performance. The only thing I can think of with the chains is that it keeps them calm. A lot of them have nervous tick-type habits, such as chewing their chain whilst in the blocks.