I think what i meant at that time, and what i would have posted now is, it would take the least amount of work to be good if you go with the race your muscles push you towards, if 10k feels easier than marathon and easier than 5k, then going with that could be your best bet.
But i have seen claims that the 50/50 slowtwitch/fastwitch type that typically run middle distance- 10ks will one day be the marathoners that break 2:00 or better..
So i think that if your not built for a certain race you just have to train a lot more and a lot longer to get really good at it.
If im 90% fast twitch it will take a lot longer to make those muscles fibers have enough endurance to complete anything longer than 400m probably..
So what im saying is although genetics may predispose us to certain race distances, they dont decide weither or not you can be the best at any race distance…
those people that were mentioned above are very buff people… they lifted to get buff… if they would have chosen to run they would look a lot different. Maybe now they will never be great runners, but they certainly could have been.
there is only one situation that i can see someone having a lot of trouble being the best at any race..
a very very high count of slow twitch fibers… arthur lydiard said basic speed is a limiting factor, i dont know if that is right or not, it might just be that gains are a lot slower or seem a lot slower compared to the fast twitch guy whos running for more endurance.
1/10th of a second off a 56second 400m pr doesnt seem like much, but it is improvement, so maybe the basic speed argument is wrong too?
My main idea is this, I really hate it when someone uses genetics as there excuse.. why not just train more/more intense, or change something.. if your weak, or slow for basic speed, do hill work/sprint work. If you are a 44 second 400m guy, then maintain that and start running long distance runs, or if you have been and dont see any improvement either run longer, run doubles (more miles) or do more AT stuff ( Progression, LT/AT intervals, Tempo ect)
And even if you hit a plateau for a long time, as most runners do, why give up or just accept this as your ultimate time..
Try some over compensation training or just wait it out and enjoy running rather than prs for that little while.
maybe im just a foolish young man who isnt even close to his peak ( 18 ) that needs to be there to know whats going on…. but i know that believing has helped me tremendiously.
i can explain how/why/when ect in more detail if anyone wants to hear it.