bor, I don't know what kind of endurance athlete you are, but if you're running atkins/ckd you're not an endurance athlete, and vice versa - trust me.
What kind of endurance sports are you involved into?! If you want to increase your VO2max and prevent innervation over long distances (or periods of activity) then fatty acids are MUCH MUCH more inferior to moderate carb + low fat + high pro meal for several reasons. One being simply that abundance of fatty acids in the blood inhibits secretion of pyruvate dehydrogenase, thus pyruvate produced from neoglucogenesis accumulates in the muscle cells as lactate - endurance goes to hell!
Over short distances though, fatty acids are superior, but short distances aren't a test of endurance really, rather speed.
Hope this helps!