Can working out cause fever blisters?

Working out itself does not directly cause fever blisters. Fever blisters, also known as cold sores, are caused by the herpes simplex virus (HSV-1). Once infected with HSV-1, the virus can remain dormant in the body and be reactivated under certain triggers, leading to the development of fever blisters. Some common triggers for fever blister outbreaks include stress, fatigue, hormonal changes, exposure to sunlight, or a weakened immune system. While exercise and physical activity can sometimes be associated with stress, they generally do not directly cause fever blisters.