It's the wrong legs, Gromit!

Wrong legs indeed, don't know what I've done with my fit ones...
After a fairly leisurely weekend, I thought I may be well rested for this weeks long-ish run. I was running from home today and had the choice of a hilly route or a flat one. I took the flat one and it was quickly obvious that was the right choice!
From the outset, my legs were tired, very tired. I had the route in mind, but hadn't measured it. There were options to shorten it along the way, but I thought I'd see how I felt.
A couple of miles in, everything had loosened up and I was bombing along! Didn't last long mind and every stride was an effort. Too many walk breaks and too many excuses to stop for some reason or another.
I did consider chopping off a loop, but decided I wanted time on feet so did the full route.
I find it slightly ironic that if I run into town, I can get in more off-road stuff than if I run the other way, towards the moor. (I live just 5-6 miles from the boundary of the North York Moors)
So, I struggled and shuffled on. The last 3 miles or so took a very long time and it started to rain as well. I got home just as the heavens opened!

When I measured my route it was over 13miles so that was ok.

I used my S!CAPS today, no idea if it made any difference or not as I don't think I was working hard enough to induce cramp... I ate all my sweets and my cheese biscuits too. I was thinking as running, I have a couple of gels I've acquired from various places (not tried one yet, don't really fancy them) and when I read the packet it says to consume one every 20 mins or so! Surely not? I shall continue experimenting with eating 'real food' while running thank you very much.

I think part of todays leg tiredness was due to last weeks mileage, but also a lot to do with not having eaten properly yesterday. Weekends just seem to mess me up!

Also, another question, related to running nutrition, is it better to 'front load' or replace the calories afterwards? Todays run burnt over 1500 extra cals and there's no way I can eat that much extra after a long run. I'm talking straight calories here, not what kind of food do you eat. So many things to tinker with!