Just read through this. Very interesting discussion. Can I chuck in some thoughts replying to the question as I think it was originally in Vrap's head ie how far can she get now ?
I reckon, in real terms the key factors are
1) optimal bodyweight. Most runners in Britain are well above this. Looking at the Kenyans etc in the flesh, at races, they are even skinnier than they seem on telly, though this applies to our elite women, for instance, too eg Paula, Liz & Hayley Yelling. Eat like a traditional Kenyan, or a Chinese etc person.
2) lifetime miles in you legs, and consistency of high mileage, injury free training. Paula had been training, I reckon 12 yrs+ at a very intense level before her marathon WR, and the same could be said of most of the elites. I, for instance, have been running for most of 23 years now, but I'd discount the first 4, and about 10 in the middle when I was cruising, and can really only say I've done 5 or 6 years, and not consecuctive of hard training.
c) age - relevant to the point made on the first page, discussing potential as a proportion of world records. I think the age-graded tables are useful pointers here, but I (age 53) don't think training needs to be limited by age nearly as much as some 'authorities' suggest.
d) motivation. Will you have the motivation, never mind other practical life isuues, to train as hard/optimal as poss for the next 10 years ? That has certainly been the main reason why I haven't done so; some years, or spells of years I do fine, then something comes along to distract me, and give running a slightly lower priority - not necessarily a bad thing, but clearly a limiting factor in reaching optimal potential.
