Catch a virus such as flu, and you would expect to be lacking in energy for a few days until your body recovers. But in some cases this tiredness persists long after the virus has cleared up. This is a fairly common occurrence, known in the medical world as ‘post-viral fatigue’. The condition has been under the spotlight recently as many people have suffered ‘Long Covid’, when symptoms of coronavirus persist for more than a month. One of these symptoms is indeed a persistent