Q.E.D.

When I ran the marathon three years ago, I was knackered for the last fifteen kilometers. With age and wisdom, I figured it was because of my dining habits. I had had only a bowl of honeycomb that morning, and dined exclusively on wine-gums while actually running.
That and I was getting over an injury that had prevented me from training as much as I would have liked.
So this time, I had been training properly. I had a good hearty breakfast and enough time had passed that it wouldn’t be sitting in my stomach while I ran. I downed four PowerGels. All the stars were in alignment so that this would be a great run.
This time… I was knackered for the last fifteen kilometers.
Really, what I can conclude is that running a marathon is hard. It is not easy. You will always be tired for the last fifteen clicks.
Suck it up, princess!