1000 miles - 1000 hours
It doesn't sound very much really - cover 1000 miles and you've got 1000 hours to do it.
But it is the same mile every time and you can only do one mile in any hour - so no putting in a few miles and then getting a decent rest.
It's 200 years since this challenge was first taken on and completed and over 42 days Richard Dunwoody hopes to do the same while raising money for charity.
Read about it at dunwoody1000mile.com - tell your friends too.
I'll post a follow-up here on the day he is due to finish - exactly 1 month from now - 10th July.