Today I thought I'd go one better and took part in the New Forest Marathon (
https://connect.garmin.com/modern/activity ), yep 26.2 mile mixed terrain running. Although to be honest it wasn't a walk in the park. I started flagging at 18 miles, then at 22 miles I bent over to adjust my laces and felt a sudden desire to lay down. After a 3 minute rest I got up and walked until I felt better, running the last mile. My official time was 4:27.24 which I can't really grumble over.