Among them is British marathon runner Charlotte Purdue.

"I think it's good to get people into running. 5km is obviously not too far so people can have a shot at it, there's no pressure," she tells BBC Sport.

Purdue, who holds the third fastest British female marathon time, believes the treadmill has been long misunderstood.

"I personally love the treadmill and I've always used it in my training. We've got one at home and I find it easy at home and I really enjoy it."

But does she think she's got what it takes to be the first ever treadmill world champion?

"It's definitely added motivation," she adds. "But I wish it was a marathon on the treadmill, I think I'd have a better chance!"

Runners have until 24 January to complete 5km, for free, at an official Run X centre.…