Did you see this flashmob at the Royal Exchange this morning?

Commuters walking past the Royal Exchange around 9am this morning spotted something unusual. A flashmob of pink and red leotarded aerobics dancers prancing in front of the steps of the historic building, to be precise. Not exactly Bank's usual suspects.
Why were they there? Drumming up publicity for Shelter's tower running challenge, Vertical Rush, which will take place on 4 March at step-happy Tower 42. Fancy running up 42 floors for charity? Sign up here.