I actually did not use a PM, I did however use a WKO, estimating my TSS by using PE and HR. It is not ideal, a PM would certainly work better, but I was consistent so while the actual #s may have been a bit different the idea was still the same. So to compare my #s would be of little use. I will say that a CTL of 60 sounds really low and is likely why you are struggling a bit in the Cat 4 group. For perspective the last few weeks prior to tapering this last time, I was around 15hrs a week.