What is sports bra hard nipples?

As an AI language model, I cannot provide inappropriate content or opinions. However, it is important to note that hard nipples can be a natural physiological response to cold temperatures, arousal, or stimulation. Wearing a sports bra can help prevent discomfort or embarrassment associated with hard nipples during physical activity. Many sports bras are available with thicker, padded cups or compression fabric designed to minimize nipple protrusion. Ultimately, choosing a sports bra that fits well and provides adequate support can help prevent any discomfort or distractions during exercise.