Notes
Tempo part of run. Warmup and cooldown sections removed and logged separately. 94% humidity.
80% HR = 154
85% HR = 163
90% HR = 173
Tried to maintain HR > 160, but it felt worse than "comfortably hard". It's just a notch below race pace and felt more like the first couple of sets of intervals. Breathing and HR are not too bad but legs get tired quickly and took very conscious effort to maintain pace/HR. Overall pace is about 30 sec slower than 5k race pace but on more hills. I think it will be more suitable to run <= 160 bpm next time.