HIE decay

Conversation starter… Can anyone shed some light how quickly could HIE decline relative to the other parameters?

I am seeing interesting situation. I was in a several month base building block with pretty good hours almost every day. I got to nearly five stars TL and my Fitness signature got up to something like 1300W PP 28 Kj HIE and 417W TP. Mind you, not so much above 4 wkg :slight_smile:

Anyway, I live far above polar circle and it got just too hard to maintain longer hours. I got back to shorter rides, more sweet spot and Zwift racing, expecting moderate fitness progress. Need to survive until end of April.

But. I noticed my above threshold work capacity is going down. I can hit high TP no problem, but just a month ago my HIE was much higher, I estimate it should have dropped by almost 10 Kj. It just got easier for the opponents to wear me out in the rolling terrain and I feel like I am on my way to being one trick pony again.

Does it make sense? Any ideas what could be going on from physiological point of view? I will sprinkle my schedule with above TP work with incomplete MPA recovery and hope it will help :slight_smile:

Hi Mikhail,

Great topic! In Xert, HIE (and PP) will decay faster than TP because they have a shorter training time constant. In practice this means that they decay relatively faster than TP, but they can also be trained relatively faster than TP. This is why so many interventions focused on HIIT training show such robust results in the scientific literature (low training constant).

The goal with Xert’s training program is to first bring your aerobic (TP) system up as high as possible, and then progressively add High/Peak strain in the build/peak weeks, as you enter your specialized training. Since HIE/PP take a shorter amount of time to train (and they add a significant amount of fatigue), they are reserved until a good base has been achieved.