Yes, today was the infamous W5D3, the 20-minute run. I really wish I could say “it was easy! no problem!” But I didn’t make it through the whole run, I made it up to about 12 minutes, and had to walk for a bit, then picked it up again for the rest of the time. Not terrible for a first try I guess; I’ll try again.
So from what I’ve gathered in my various athletic experiences, there are two different kinds of “tired”. The first one is a cardiovascular overexertion, where you’re gasping for breath and your heart is pounding and you’re afraid your chest will explode. (I am naming this “Type A Tired”.) The other kind is where you simply run out of gas– your body is having a problem getting the energy it needs to keep going. (“Type B Tired”)
Today was a Type B Tired. I run at a pace such that I don’t approach Type A Tired (unless a hill or something gets in my way) but there’s not much to do about Type B out on the trail except fight it out as long as you can.
I’m imagining a conversation between my metabolic system and my liver (based on my limited knowledge of how it works)… basically my metabolic system is cussing my liver out. “What do you mean you’re out of glycogen? Can’t you tap some fat reserves or something?” (If I could solve that problem I’d probably make a lot of money, heh.)