Today I learned the value of a good warmup. It's Tuesday. My speed workout day. Typically, I run a 1 mile warmup, then do a speed warmup 800 or 1600, running at right about marathon pace. Then, I go into my actual workout. Today, I was scheduled to run 5 1600s. However, I was running a little late and decided to forego my speed warmup. Big mistake. I was done after my 2nd 1600. Tried #3 and was almost thrown off the treadmill because I was already dead tired.
Now this might have been because I was dead tired. Five to six hours of sleep ten days in a row will do that, but I also think it was because the shock of not being properly warmed up completely threw my body for a loop.
The really funny thing is that I can run faster eight miles into a run than I can one mile into a run.