Wrong feeling and HOP

Because the weather was bad I jumped on the Kurt for a workout called Needham. What is Needham? Needham is an hour of power, aka HOP. This workout was introduced by Bill Black, a US coach and someone who contributes very much to the wattage forum.

Now, what is the HOP. The HOP is a workout which -as stated- is an hour long on an intensity of 90% of FTP (so around sweetspot). Now, as if that sounds hard, it becomes harder due to the short bursts you after -say 4 minutes of about 20 - 25 seconds long. I have only done these workouts on the trainer and I always find them to be very exhaustive. You know you're gonna suffer and you know you're 'cooked' very slowly. The last intervals are always hard to maintain, at least that is my experience with this workout. Nonetheless, it is a very good workout if you can sustain. If you have not done this before try to build it up from say first 20 minutes up to an hour, because as I said it's quite stressful. Below you can see the profile:

The workout starts with 8 minutes warmup. After that the hour begins with a short burst. Now, as you can see the first 26 minutes of the HOP data is missing (straight line upward). That was because Trainerroad got stuck (my laptop is getting slow, some processes were running on the back). I then decided to ride 'on my feeling'. This meant a cadence of 88 at the gear I selected. I decided to just try to ride 1 hour flat since I did not have any hope that Trainerroad would start again. I 'hoped' to ride at approx 90% of FTP.

Now. Suddenly you see my data appearing again at around minute 32. You see that with the cadence/gear combi I selected I was constantly doing watts at FTP. So the first 24 minutes my feeling was wrong and I rode 'too hard'. After I could see my datastream again I decided to switch to the HOP profile again. As you might see from the red line (Heart rate) is trending upwards. This is the decoupling effect I was talking about. Every step further away in the hour my heart rate has more 'trouble' getting back to a stable level. After every burst it 'steps' up. The last 6 intervals average heart rate equaled. 153, 156, 158, 159, 161, 165 (OK the last one I pushed it more). Dehydration is one of the factors in place. The other is just fatigue I guess. Again, heart rate as a monitor for performance...maybe not.

End of the HOP I averaged 272 watt instead of 256 watt (which was the 90% FTP target). Intensity was 0.9. Total ride TSS was 98.