What is the longest race event in the men's summer Olympic athletics programme?

The longest race event is the 50 Km Race Walking event which comes in at 31 miles. Before you think, "Well it is just walking" take a look at the record times! Jared Tallent completed it in 3 hours and 36 minutes! That's under a 7-minute mile which is crazy fast for walking which requires one of the feet to be on the ground at all times.

https://en.wikipedia.org/wiki/Race_walking_at_the_Olympics

https://en.wikipedia.org/wiki/Racewalking

The 50 kilometres race walk is no longer part of the Olympic programme. It has been dropped after the 2020 Tokyo Games in 2021 and is going to be replaced by a marathon race walk mixed relay for Paris 2024.

https://www.insidethegames.biz/articles/1135696/olympic-race-walking-event-paris-2024