Don't whine like a baby. That won't get you anywhere. Instead work the system. Get yourself on the agenda for the next school board meeting or a meeting with the principal (if you want action sooner). Petition to allow you to run with no shirts, explaining that it's legal and the disadvantages that you suffer because of it. Bloody nipples is a legitimate concern. Ask if the board supports policies that will result directly in pain or injury to the athletes. If it happens, document it with pictures and/or an email to the coach/principal.
They will likely respond with a regurgitation of school dress code, and how they don't want bare skin, etc. So counter with a petition for equal treatment across all genders, sports, and extracurriculars. Ask if the cheerleader and other spirit squads' uniforms meet the school dress code (i.e. skirt length, shoulders covered, no bare mid-rifs, etc.) Point out that the swim team swims without shirts and they should be held to the same standard. If girls are allowed to run in jog bras or swim in tanks, ask that they be required to cover up too. If they argue about "decency" counter with "there is nothing indecent about the human body". If they continue, then extend the decency argument to swimmers or gymnasts that wear bikini bottoms.
In the interim, you could get all of the guys to wear jog bras to practice and wear those instead of being shirtless.
But if you want to change the system, you can't act like a spoiled brat. You have to be logical, practical, and unemotional. When you meet with someone in charge, wear nice clothes, be polite and respectful.