Well I have been riding to work twice a week - 26km each way - for some time now (100km).
I'd decided to up it to 3 times a week (150km) so two weeks ago I started.
Then bugger - had a heart attack while riding and crashed - right next to the ambulance depot - and in front of a car with a CPR instructor in it.
I woke up in hospital with 2 stents in my veins - a pill program that makes a drug company recession proof and looking forward to a long rehab program.