I know I’m old because I have similar thoughts and opinions when I see that. And yes I have daughters which I’m sure is a big reason why I feel that way.
Sports bras are much less revealing than most two-piece swimsuit tops. They’re thicker, the cut is more modest, and it’s fucking hot out!
I’m with you on running in a thong. How can that be comfortable? I tried one just for daywear, and no frigging way.
You must freak out when you see elite women distance runners, who compete in bunhuggers.
Indeed. Sports bras are perfectly modest, and, at least to my male eye, look very comfortable. Frankly, if I could run in my underwear, I would. Although in truth, most of my running shorts are shorter than boxers, so I pretty much already do.
Of course, tiny shorts and figure-hugging tights can be sexualized. But I’ve been part of running communities for over a decade, and in my experience, skimpy clothing is simply the norm. The women I’ve run with are more interested in efficiency and comfort. And the men seem seem to see such clothing as normal attire, rather than erotic invitations. I’ve never noticed a male runner comment on a female athlete’s body in a sexualized manner.
Of course, I’m a man, so I miss seeing such things. I’m not so stupid as to think that every male runner is a chaste Galahad, and I know that we have our abusers and misogynists. Female runners aren’t immune to sexual harrassment, any more than any other woman. But it seems to me that in terms of attire, athletes, like actors and models, have a different attitude to their bodies, that manifests as a higher threshold for “immodesty” than, say, a dad with teenaged daughters.
Living in NJ, I see people running in the relative extremes of weather, out on blustery winter days with < 20F temps and running in sweltering > 95F heat with humidity. I really can’t go colder than 45F (no wind please!) or hotter than 85F (no humidity please!), so I always notice those brave souls doing their thing in the most unpleasant temps.
That’s not for me, and that’s why I have a membership at the YMCA, where they have an air-conditioned indoor running track.
As far as running attire, I go to A.C. Moore and purchase a stack of 10 T-shirts in a garish orange color, and accompany them with proper running shorts. Day in and day out.
I imagine there are people who wonder if I ever wash my shirt as they are all identical.
As for those other runners, whatever floats their boat. I can’t imagine running in the gear they use or in the temps where they run, but then again I only have to worry about me.
I don’t see them because watching distance running is almost as dull as fishing, but those are at least opaque. The only near-Olympian woman I know would never dress like that for her event, but that was bobsled. 
ETA: She tried out for American Gladiators, where she’d wear less, but they already had a beautiful blonde.
Well, there was the British bobsledder Gillian Moore, whose skinsuit split at the seat when she was starting a run in 2010. The world discovered that she was, in fact, rocking a thong. Which I suppose is a logical choice when you’re wearing a skin-tight coverall designed for maximum aerodynamic efficiency. I’d link to the video, but I’m at work.
And I object to your assertion that running is “almost as dull as fishing”. Nothing is as boring as fishing. Save maybe soccer.
<ducks and runs> 
I tried running in a thong once and it was sooo uncomfortable. Then I realized that I had it on backwards.
You’re welcome.
I, for one, applaud the contemporary trend of women’s athletic tights with transparent mesh panels.
In view of our modern moral code, I assume they will be completely transparent within the next year or two.
Synthetic wicking material shirts are much better than cotton for pulling moisture away from your body, but now they’re no good for the environment as evrery time you wash them microscopic threads come off & get washed down the drain where they get ingested by small fish & make their way into the food chain.
Gillian Cooke.
I would tend to think that men typically generate significantly more heat when working out than women. They are generally heavier, which means more calories burned during exercise. And they have more muscle, which produces heat as it is activated. So it could be that whether a woman exercises in tights or shorts doesn’t really make a whole lot of difference to how warm she feels.
I wear full sleeves while cycling and cover as much as I can when exercising outdoors.
I am white. Super-duper-glow-in-the-dark-beacons-are-lit-Gondor-calls-for-aid-WHITE, so I cover up as much as I can to prevent sunburn. I wear 3/4 leggings over shorts because it really doesn’t make me much “cooler” to wear shorts while working out, and I hate it when they ride up.
Whoops. Thank you.
This is where I stand on it as well.
When I see other runners I often wonder how some can wear so much, but I’ve never considered critiquing them for it. Mostly what I think when I see other runners is, “Good on ya! Way to get out there.”
How about watching fishing?
Oh yes, nifty stuff! Alas, it also does nothing to protect my pasty Irish legs from the sun, and is a whole 'nother step to take when pulling on a pair of pants takes 5 seconds. Quite useful when wearing skirts in summer though, and for the ahem…better endowed lady!
I wear either capri tights or full tights every time I run no matter what the season. Yeah, I could wear shorts, but I’m a heavier woman and chafing between my thighs is a problem. It has nothing to do with fashion and everything to do with wanting to walk normally later.
Like Nava, every step I take I’m yanking and tugging and shifting around trying to get comfortable. They ride up my ass, into my crotch - so uncomfortable. So yeah, fuck that shit.
My absolute favorite running tights so far are a pair I got from Target. They’re soft, breathable and they have a normal-sized pocket I can actually use, which is remarkable for women’s clothing in general.
No, they’re not.
Bathing suits are not underwear, even when they’re bikinis. And the sort of sport bra designed to be worn as the outer/only layer is also not underwear.
What’s underwear and what’s outerwear has nothing at all to do with the amount of skin revealed; or with whether the name for the piece of clothing contains a word used in previous times only for underwear. It’s entirely a matter of what the society thinks normal at any given time. People got used to seeing bare ankles. People got used to seeing uncovered hair. People got used to seeing bare calves, and bare knees, and bare lower thighs, and bare arms, and bare armpits. People can get used to seeing sports bras out on the street. You can get used to it too.
This. Very much this.
Being confused about whether particular clothing causes overheating is one sort of thing – many people don’t realize that the right clothing can be cooler than bare skin. Going on about whether people should be wearing clothing in public that’s been worn out in public for, I don’t know, maybe thirty years now? is another sort of thing.
And while I’m at it, posting video of what I gather is an athlete’s basically bare ass that she didn’t intend to show off to the public is a third sort of thing; and not a pleasant sort of thing, either. I’ve got nothing against bare asses, even in public, if the people want to show them off. Spreading around video of people who didn’t want to show theirs off is showing one’s ass in a different sense of the term entirely.
I’m a guy and always wear the supertight man-spandex under my running shorts for the same reason. In the winter I use the moisture-wicking ‘tights’ to keep my arms and legs warm.