I wouldnt say it's necessarily just down to conditioning, Donegal have some absolutely huge men. Murphy, McGee, thompson, McFadden etc. Even their smaller players are naturally stocky/powerful (yes, I know their conditioning is great but its aided by the raw material). Align this to great experience and more importantly brilliant footballers like ban Gallagher, mc hugh mcbrearty off the bench, gallen etc and you've what I consider and have considered for the past 2 years to be a genuine contender to match the dubs.
We simply don't have the players to compete with them, that's the high and low of it for me.