This is an interesting thread. My wife's dad was quite a good runner (1:29 for a HM at about 45) but had a heart attack while out for a jog in his early 50s (he is okay now by way and in his 70s). They also were watching me at 25th GNR when someone collapsed in front of them and subsequently died.
As a result my wife and kids are very opposed to me doing a full marathon and don't really like me running HM for fast times (although I can get away with this because by time I have finished the fact I didn't run nice and easy is a bit too late to do anything about!). So up to now I have still not done a full M.
I am working towards them feeling more comfortable about this by doing a lot of running and think if I get up to training runs of nearly 20 miles as part of HM training - most is 16 miles up to now - then they might feel more relaxed about it.
But every year someone dies in GNR or LM then this reignites their opposition.
The one big plus point is that I am so much more fun and have so much more energy when I am running that they can see that it is really good for me - better to be running and feel alive than be a couch potato and feel lethargic all your life whatever the risks surely? Of course their counter argument is that this can be achieved with 5 mile runs, there is no need for 26 and, in all fairness, they are probably right!
