The training plan just called for a simple 6 miler although I ran fast as I left a bit later than I had intended. Canary Wharf to Catford was only 5.5 miles but I arrived with 6 minto spare so thought I'd tack on a bit extra - looping round the park at Catford. Unfortunately the loop was a bit longer than I expected so had to take a short cut down a little alleyway which I felt sure would take me back to the station... with time running out I found out that it actually led to a small car park with a 7 foot wall separating me from where I wanted to be... in the end I just had to climb over it, so am adding scrambling to my marathon skillset!