The back on the horse theory, I can safely, say, is accurate. Nothing too complicated tonight, just my simple 20 minute treadmill workout of death. I was thinking of doing the 45 minute routine, but due to my fatigue today, I decided to take it easy (somewhat) on myself today.
At the end of it, I cranked out a 2 minute sprint at the fastest speed the treadmill went. I felt so good and my lungs didn't even hurt that much. I think the endurance is being built up real nicely right now, which will be good for multiple reasons later this year.
Got workouts planned for tomorrow and Sunday as well. Going to Denver Sunday night, so I know I'll get some "unconventional" workouts in, as well as hopefully some more running outside. :)