I did a long Zwift ride last week at a Tempo/Threshold pace. I reached the wall on my second climb up the Watopia KOM while chasing a group. According to my activity, my MPA never really moved off my Peak Power levels, but I know I hit the wall on the way up and couldn’t hang on anymore. Trying to understand if that’s a lack of fuel, lack of aerobic fitness, etc. Can I decipher that from Xert data?
Currently MPA will only decrease when riding above threshold. However, we know that long endurance rides are likely to deplete muscle glycogen stores, which is one of the largest contributing factors to “hitting the wall” or bonking. In general, the higher your training load, the more capable you will be to complete larger rides without bonking. We don’t currently model this, but we have some ideas on adding an endurance energy component to the Fitness Signature. We will continue to develop these ideas moving forward.