Why won't my Covid-19 symptoms go away?

Elly, 37, was training for the London Marathon when she says she started to develop Covid-19 symptoms in March and, almost six months later, she believes she's still suffering from them. Similarly Meredith, 22, who is a keen cyclist, first noticed her symptoms in April and doesn't think she has fully recovered. The Royal College of GPs says there needs to be a national network of post-Covid clinics to help those like Elly and Meredith.