Why do my toenails go black when I run?
For regular runners black toenails are a common occurrence and mean that you always have to have a pot of nail varnish to hand! There are three main causes of a black ‘badge of honour’: shoes that are too small; a toenail that comes into contact with the roof of the shoe too often; or if you grip with your toes too hard when running. Essentially blood vessels under the nail burst, leaking blood into the area. This can cause swelling and cause the nail to separate from the nail bed.
If the pressure becomes painful then you can drain the blood using a sterile pin. However, if not then it’s best to leave it alone to heal naturally.
Louise has been running for over 20 years, with the last 16 of those at International level. She has represented Grea...