Why I row to HR - 30r20 75% HRR

Perfect example of why I use HR to govern the bulk of my ergs - although it would be obvious that I would be tired today both mentally (due to lack of sleep) and physically (yesterdays 4by750 following on from Mondays 12by1min) it would be hard to work out how much to drop pace on one of my core sessions without the HR - Monday and Tuesday saw this session at 1:47.5 pace (8,369m both days) where as today we ended with 1:49.1 (8,248m) a drop of 121m - this isn't a drop in form this is showing that the body is fatigued and as such this lunchtime will see a "easier" session than I would if I hit a better pace. Still good training and certainly got a sweat on.