After a first km of 5:46 mins, I really thought today was going to be the day I would finally break 6:30 average.
Unfortunately, the heat of the day conspired against me, with a dismal 7:03 fourth kilometre putting the nail in the coffin.
Still ended up with a very respectable 4.54 km (equal best in this challenge) in the thirty minutes at an average pace of 6:37 mins/km, average heart rate of 151 bpm.
Followed it up with a game of soccer where I ran 7 km.