Thanks for the comments everyone. For me, I think it will benefit me to do the extra miles if I'm having a good run. Today, I did a 16 mile run that took in 2 miles of going up a mountain, quite literally. It was definitely a hard slog but I feel I have a marathon in me. It's given me even more confidence towards going for that marathon. As for 'ultra' I'm not so sure. I'm 45 years old, but don't believe that age should be a barrier for most things, but am not so sure I could commit to the training I suspect is needed. But i am a competitive so and so so who knows. I will have a look at that link, cheers stanmorek, and will pop over to one of the ultra threads to see what it's all about, cheers Debra.