Just had what may be the fastest non-race run I've ever done. Despite the heat and humidity of a late afternoon Florida thundershower (73 F, 82% humid), I hit the optimal dose of caffeine and plugged into some fast paced music and ran out. The overall pace was 6:50/mile for 4 miles, total time 27:20. This includes a mile of getting warmed up, and if you take that out, I ran the last 5K in just under 20 minutes. Felt great considering the far-from-optimal conditions, not being in the excitement of a race, and not being in my running flats!