Today, I did my usual double set (for which I got some weird looks, again). Anyway, I had been doing 50 minutes with a 10-minute break and a 40-minute follow up, for a total of about 6.5 miles. Then I figured it might be better to do two set of 45 minutes because that way I have a better comparison. The discrepancy between the 50-minute and 40-minutes sets was vast; however, the two 45-minute set came out about the same today. That's good.
I was exhausted though. I started yawning before I even walking in the gym, and it was a good 30 minutes and 2 miles before I could stop. Probably only stopped because I had to regulate my breathing for so long. Regardless, I got in 6.19 miles while I was there, and then some more.
I'm still yawning, so I am going to go try to remedy that.