Back to break another world record?
Not this time. Paralympian Hannah Cockroft, who won two gold medals at the London 2012 Games put forward a very different challenge yesterday: she laid down the gauntlet to Boris Johnson, asking him to spend one day in a wheelchair using public transport to see the difficulties she and many in her position face.
Did the mayor accept?
He did not. while he seems happy to take part in charity tennis matches or tackle the zipwire, he's turned this one down. A spokesman for the London Mayor said that while the Mayor of London was "very aware" of the difficulties which disabled people face when travelling in the capital, he would not be accepting Ms Cockroft's challenge.
What problems has she faced?
Putting forward the challenge on ITV news yesterday, Cockcroft - who holds the world record for the 100m and 200m T34 wheelchair sprint - explained: "I constantly am having to get in a taxi... I have often been turned away from buses because I am with another person in a wheelchair."
And it's an ongoing battle?
Last week disability campaigner Anthony Ince posted a YouTube clip parodying a viral video in which a man sprints from a Tube carriage to the next station and catches the same train. In Mr Ince's version he gets stuck on a set of stairs and a written message reminds us that only 25 per cent of underground stations have step-free access.
What's Boris doing about all this?
Mr Ince's video was hailed a success yesterday when the Mayor's office announced plans to spend £75m on new lifts for the Underground. Mr Johnson's spokesman said: "London has one of the most accessible transport networks in the world, but delivering continued improvements is a key priority for the Mayor." Not that he'll be trying those improvements out himself, of course.