As I said yesterday, I fully intended a 400 meter workout today. That's what I just did. I also said it would hurt a lot, and it did. After my 1 mile warm up jog, I ran 10X400m, with a 60 second break in between each 400. I ran each 400 at between 83 and 87 seconds. If you break that out, that means my pace for all the repeats was roughly 5:32-5:48/mile. I was hauling pretty good from the get go.
This is also why it hurt so much at the end. However, that's what I wanted and I could feel the burn from the lactic acid in my legs getting deeper as I went. As you progress forward with little rest, you don't give your legs full time to recover. A little recovery and a quick startup makes it a bit more difficult each time.
Tomorrow, I will easy run for around 6 miles to loosen up the legs and recover. This weekend will be busy, but I want to try and get in a little something, like a 4 miler. We'll see.