Sinfield said the ultramarathon challenge was also in honour of his former Leeds Rhinos teammate Rob Burrow, who died from the disease in 2024, aged 41.
Sinfield said he hoped to raise £777,777 during the challenge, which would add to more than £10m fundraised since he began running marathons in 2020, following Burrow’s diagnosis in 2019.
Dr Francesca Crawley from West Suffolk Hospital said Sinfield had “done a fantastic job” raising money for MND.
The hospital is part of the MND-Smart trial, which tested potential new treatments for the disease, as well as looking at whether existing treatments for other conditions could have some benefit.
She said the condition could often be misdiagnosed as it could “present in many different ways”.
“The disease deserves a lot of research. I think we are probably quite far from a cure,” she said.
