Running is great WES, don't be disheartened by your calf injury. I am sure it will only be 3-4 weeks that you will be a little bit short for. After that you should follow me on Strava. It's a wonderful way of boasting to your friends how far you can run in one go. Just the other day I received several kudos' from people after I had been on a 10 mile run.
You can do a circular route from Limehouse basin. Up the Limehouse Cut to the Lee Navigation/Lea River then up to Hackney Wick, then Hertford Union Canal to Victoria Park and back south on the Regents Canal to Limehouse. There's a a ten mile route in vol 2 of the Time Out book of London Walks.