Day 1: Speed round Happy Valley

Figured I'd try and run as fast as I could for 6k. It was pretty warm today (the thermometer by the bowls club read 32 degrees at 10pm) so maybe 6k was overambitious. I did a lap's warm up at about 145bpm, then ran as hard as I could for 5k. Well, as hard as I could for 5k, rather than [as hard as I could] for 5k, which would probably involve sprinting a hundred yards and then staggering the rest. Splits as follows, avg bpm in brackets:
3:55.95 (170)
4:26.59 (175)
4:17.21 (181)
4:18.34 (184)
4:24.19 (186)
Obviously tiring on the last k. I think that crappy second k is partly to do with slowing down to put my bottle down; but it's difficult to run in this heat and humidity without drinking all the time, so that's a hard compromise to decide on. Had a vanilla Gu before I started as well, which probably helped. It had caffeine in it, but happily no stomach cramps, as we runners euphemistically refer to 'fighting as hard as you can to not shit your pants'.