So I finally did my first, official, planned two-a-day yesterday. Started off the morning with a 5:00 AM run of 6.5 miles on my hilly route. After the hills of the Wild West Relay last weekend--at 8500+ feet altitude (race report coming soon...let's just say it wasn't AT ALL what I expected...)--I realize that consistently running my hilly routes more often, as I have done this summer, has really made a difference. My legs simply don't get tired, and I am able to keep my pace consistent on the uphill. This is definitely a good thing.
My second session of the day was after work, at the rec center on the indoor track. I did 31 minutes, which was probably about 3.2-ish miles. Surprisingly, my legs were not tired, as I expected them to be. I did 10 minutes at 9:30 pace, then sped up to 8:15 pace for 11 minutes, then back to 9:30 for 10 minutes. If I'd been outside, I probably would have kept going, as I felt pretty good. However, the indoor track was monstrous and I was not enjoying all those right-hand turns, so I threw in the towel and did some core work instead.
Overall verdict: Thumbs-up for two-a-days