2x20 minute tempo workout. I felt unusually labored, possibly from pollen allergies. The evening was beautiful, with a radiant sunset and a temperature of about 18 C. I warmed up for 16 minutes, ran my out-and-back with a 3 minute rest, and cooled down. I deliberately ran the second bout at a reduced intensity, as I felt like I was killing myself on the first bout. Instead of trying to hit a particular intensity on the second bout, I concentrated on keeping good form with upright posture and consistent foot (ball) strikes.
5.1 km splits: 19:29 (wee bit too fast), 21:19.