Running 30:58  4.96 km (6:15 / km)
ahr:131 max:158 shoes: Inov8 Parkclaw 275
Margaret River Parkrun - 10 mile brook trails. Even though I started very conservatively, the warm morning with very high humidity (90+%) brought HR and breathing problems on quite quickly, and had to slow right down after the first km in 6:03. All of the max HR above 140 occurred in the 600m-1400m segment, after which it was below 130. Second km was 6:55, then stayed conservative for the rest of the run at around 6:00/km, although the last km was 5:50 when I knew I'd be ok to finish stronger.
Got 31/69 and 2nd in my age group, although the local dude was 4 mins ahead.