| There's also value in spending some time in zone 5 [1]: this is where the heart is really trained as a muscle, and where the cardiovascular system is pushed to its limit (the famous vo2max: increasing vo2max is done in zone 5, for ex. with HIIT [2]). Zone 2 is all about giving the mitochondries a chance to get better at providing a steady energy flow over a long time, mainly by optimizing for burning fat as fuel instead of glucose, avoiding lactate accumulation during the process [3]. In between, in zones 3 & 4, you get a little of both those ends of the spectrum, it's still helpful to a degree, but it's not really optimized: that why it's deemed preferable to spend the bulk of your training time in either your zone 2 or zone 5. The ideal composition of a training period seems like 90% zone 2 and 10% zone 5, and going for more than 1h of zone 5 per week seems not that interesting. Also, mixing zone 2 and zone 5 in the same training session is not ideal, it's better to stay focused on one thing at at time. [1] https://peterattiamd.com/category/exercise/high-intensity-zo... [2] https://peterattiamd.com/category/exercise/vo2-max/ [3] https://peterattiamd.com/category/exercise/aerobic-zone-2-tr... |
I've spent a lot of time reading a lot about opinions and then looking at logs of professional athletes [1] (in cycling as I am most interested in that). My conclusion is that training comes down to:
1)do a lot of volume, the more the better
2)do some "hard stuff" - if those are hard intervals, longer "sweet spot" intervals or a a mix of those (like 5 minutes at threshold and then 15 seconds sprint, repeat n times) matters little
3)at pro level do some training specific to what you are going to do a lot in racing
1)is by far the most important and the most reliable predictor of overall fitness
[1] https://www.trainerroad.com/forum/t/pro-elite-training/14046 - is a nice thread with a lot of rides from whole weeks or months of training posted with power/heart rate data for various World Tour riders
[2]https://www.youtube.com/@sportscientist - Stephen Seiler's youtube channel; he has done work on analyzing how pro athletes train but his conclusions are very simplified and it seems made to sell "polarized" training idea. When you look at the details in the data no one trains like that, the final distribution is almost always pyramidal, not polarized