Gym fashion is stepping up these days. Workout wear is now built to go from gym to street. There are even fancy sports bras to give fashionable support.

With all the attention that is paid to what others will see, not much thought goes into selecting undies for the gym. Those snug cropped pants might suggest wearing a cute thong to avoid panty lines. What you may not realize is how much bacteria that thong can transfer, leading to vaginal and urinary tract issues.

Don't wear your cute panties to the gym. Wear something that breathes, like cotton panties. If you decide to go commando, be sure your gym wear wicks moisture away from your body. You definitely don't want to wear those sweaty panties for the rest of the day, either. Shower and change (at least your underwear) after your workout to avoid bacterial issues.

Dr. Karyn Eilber discusses the best undies for working out.