Facial Piercings
Research shows that facial piercings can disrupt the facial trigeminal nerve. This nerve is what connects the central nervous system to facial sensations. Getting pierced in the wrong spot can trigger dizziness, eye misalignment, and loss of balance. This moreso goes for piercings of the cheek, forehead, and chin, and not so much the nose. I just liked the photo of this girl.
Serious runners wear protection!