How cold it grows and nobody sees how shaky my knees: nobody cares how steep my stairs

I had the strangest experience today while running. I had only had a little problem running but was able to do the usual up until minute 23. And then I started feeling weak. I didn't do anything different. And then at minute 24 I put it up to 7 mph for the last 2 minutes of running. And then I felt waves of weakness. I actually thought for a moment that I was going to pass out. I decided to slow it down to 3 mph and try to catch some strength. I just walked the rest of the time, getting up to 2.33 miles in 30 minutes.

I went to cook dinner, and while waiting to make some sausage, I was shaking so much I had to make a quick sandwich just to get some energy into myself. It still took about 20 minutes before I stopped shaking.

I haven't felt sick or weak all day long. Felt normal, except for the back and shoulder pain. Ate well all day, maybe just a bit more than I should have but not too much. I had mixed berries, a good serving of pineapple, a banana and raisins: very good day for some fruits. I had plenty of fiber and calories. I don't know why I was so weak while running. It was frustrating, but at least I was still mobile for 30 minutes.