Keeping the Ergo Ego in check - 30r20 80% HRR

so following on from this mornings row and blog I set off down to complete one on my "tougher" sessions for the week - that being a 30r20 with a HRR % of 80 plus - this being the start of this journey I opted for the 80% HRR target (160) and after a 1k warm up (I know extravagant) got stuck in. Felt like a beast at the start and went through the 6 minute mark feeling good (this is often the place I know if it's going to come apart) but as all seemed well I kept the drive on and got the HR up to 160 at about 10 minutes - then just peeled back the pace to stay on target - I could have chased down the 8500m+ at the end - but that's not the box I need to tick