On October 4, 2020, The Countess of Wessex joined Tomas Cardillo-Zallo, a member of Mencaps Learning Disability Running team, for the first 1.5 miles of his virtual London Marathon 2020, held on the Long Walk in Great Park in Windsor. The Countess, who has been Patron of Mencap since 2004, run 1.5 miles in support of Mencap - the marathons official charity partner for 2020 - to represent the 1.5 million people in the UK with a learning disability.
The Countess of Wessex is the first working Royal Family member to take part in the London Marathon. However, non-working royal Princess Beatrice ran the race in 2010. The Royal Mencap Society is a charity based in the United Kingdom that works with people with a learning disability.