Breast sweat: no one is talking about it, but we all suffer from it (and it's not just at the gym). If your breasts hang low, then the area underneath your girls is likely to get sweaty. That perspiration could cause rashes and irritation if you're not careful. Apply a spray deodorant or baby powder before putting on your bra to help with it. They also make these handy bra liners, which are like pantyliners for your breasts — how clever!