First of all I want to acknowledge that I am new to the sport. I am coming up on being in the sport for one year, therefore I realize my perspective may not be as broad as many of you. I am however an active female fighter in the sport and felt the need to share my view and thoughts in this as well.
I would like to make some points before I begin my thoughts.
Rocca mentioned that there are plenty of sports bra like historical examples of garb, and Varadin asked why not use those? I second that question. Why does it HAVE to be a commercial sports bra? Why can't someone take the time to make/buy a garb-like equivalent?
Second. Rocca mentioned that a logo-free sports bra is equal in garb status to a neutral colored t-shirt. She is correct. But even the t-shirt must be covered with a tabard or tunic according to our book of war.
1.2.1 A tunic or tabard covering the torso.
1.2.1.1 Neutral colored t-shirts, with no visible printing, or sports bras may be worn underneath a tunic or tabard.
So..currently they are equal. That doesn't really point towards commercial sports bras being on the same garb status of not having a tabard covering them or of being topless.
May I also point out there are no specifications as to how much coverage a tabard must have? Just a thought..
Unfortunately, the only way for women to really enjoy the same benefits males do by going topless is to well...go topless.
I will put a disclaimer here saying that I do not actually support this path of action due to the fact that most of society would freak out. However, when it comes down to it. That really is the only way. A commercial sports bra is not going to be any cooler than a tunic and will in fact greater restrict airflow to the very area most are seeking to cool down. I will also point out here that there is no rule stating that a woman must wear another layer under a tunic, or tabard for that matter..though I'd suggest ties/binding on the sides. I personally could not comfortably take advantage of this, but there are women who could.
Now one thought for getting the same visual effect would be to have a sports bra-like top that is flesh colored (either by dying/modification/etc), do a ton of make-up work to make it blend and bazam, you look semi-topless in photos, congratulations. But that still isn't a off the shelf commercial sports bra.
Also to my knowledge there is no rule against using a sports bra as a base and modifying it to look like a female garb top. Add fur, or fabric, or chain-mail, or..feathers or whatever you want. Bazam, again I believe it then falls under garb and is no longer a commercial sports bra.
Personally I see no benefit to allowing unmodified commercial sports bras (without logos) to be minimum garb. They don't equalize male and female fighters (unless you are going to require males to wear one too instead of going topless...), they ruin photos, and they allow minimum garb to sink down even lower.
See, for me it isn't that the rule currently bans bra or sports bra LIKE tops for women. What it bans is blatantly modern sports bras from being worn without a tabard or covering of some kind. Therefore I don't see why we need to allow them when female fighters (and males for that matter) are, and have always been free to create garb with as much or as little coverage as they see fit.
For instance, I highly doubt any male or female fighter/herald/belegarth participant would object to a female fighter walking on the field in this or the multitude of female fighting garb images that popular media provides us:
Personally I want as much coverage as possible seeing as I have found that weapons coming in contact with bare skin, especially if it is exposed to the sun, hurts WAY worse than covered skin, but hey, that is their choice. I apologize if this is not appropriate for this thread but this video makes my point rather well I feel.
http://www.youtube.com/watch?v=OTGh0EMmMC8My last and final thought is this. And please understand that I mean no disrespect or offense to anyone. However, I am generally disappointed in society as a whole (and this inevitably spreads into Belegarth) with the idea that "since men can operate at this level of bare minimums (either in clothing, behavior, or any aspect of life), so should we!". Personally I feel that that is a giant step in the wrong direction. If anything I feel that if an inequality is found, that whichever gender has the lower standard, that is the one that should be brought up. It shouldn't be a matter of allowing the other to slip down. But that is my personal opinion and I understand and respect that it will remain so.
At this point in time, due to the options availible to females already that I presented above, I do not feel that there is currently an inequality that needs to be, or will be properly addressed by the changing of the sports bra rule. If there is any inequality, it is in the fact that men can go topless and females can't. And sadly that is not something that will be, or can be truly addressed or solved by allowing commercial sports bras.... In order to be truly equal in that aspect, we will have to take that up with society as many big cities across the United States have done or are in the process of doing.