Posted: 09/03/2015 at 21:50
I use Coverwise, had to disclose a few running injuries as I've had physio and didn't want to get caught by the "undisclosed" issue.
They were really friendly and said marathons were no problem and would be included as standard.
I have their annual Silver policy is well under £50 including winter sports and has what I think is good cover. Even cheaper via a cashback site.