Ruben Treurniet is due to run the half marathon at the Amsterdam Marathon to raise money for long COVID research, inspired by the illness of his brother Lex. The fundraiser has raised more than €2,000, and Ruben hopes to reach about €3,000.

Lex said his health deteriorated after a further coronavirus infection at the end of 2023. He spends most days in bed, has little energy and said he is able to go outside for only about half an hour a month. He receives support from family, online friends and his kitten Mila.