In reply to DougG: Cheeky..
Of course being 5 kilo's lighter will help, but I'm coming from a background as a keeper where size and power were essential. So I'll slowly try and drop it but while eating a normal diet. Imagine running holding 5litres of water. You'll be slower with that weight, but weight alone is no reason not to be running fairly competitive times. The average build is no reason not to be putting in decent times. I think to break into that top bracket then yes, you've got to get the runners physique, but many concentrate too much on weight, almost like it's a handy excuse why they aren't running low 30 10k pace (not that I'm saying you are). If you catch my drift.
I beat guys who don't have an ounce on them, and guys will beat me who are bigger than me, because the ones who train best, do best.
One of the best runners in Wales came from a background as a flanker in Rugby, 6 foot plus, broad and powerful, he's dropped weight slowly and his times have improved. But almost immediately he was running very fast 10k's, but has now gone down to sub 31 10k's. But even as a relatively heavy runner he was lightening.