In reply to davy_boy:
I went to all that trouble for the Etape 2012 - a friend of mine is a cardiologist, so agreed to do the med certs for all of us. Cue trip up to London to see her, interesting echo of my ticker and a few questions, resulting in a formal letter from her.
Needn't have bothered for the amount of attention the staff actually paid it at registration. Bear in mind that they are un-trained volunteers in a foreign language with a queue of people behind you - how much attention do you think they'll give it, other than it's there, along with your proof of ID and entry? They're hardly going to write to your doctor to check.
Assuming you don't have any specific medical reasons why you might have any problems, make up something formal-looking and sign it yourself - I'm sure plenty of others will have done just that.
