Ok, this is a question that has been on my mind for some time. In shorter steady state aerobic race efforts (time trials), how important is fat oxidation really?
Let’s suppose we’re talking about time trials lasting less than 30mins, which just happens to be the usual format where I live. Looking at the graph below, utilization of fat seems to cut off at about 85-90% of vo2max.
As shorter time trials are probably raced at an IF of about 1.05 or so, wouldn’t that mean fat utilization is slim to none? FTP as a percentage of vo2max seems to be in the 78-85% range (https://blog.trainerroad.com/how-vo2-max-work-makes-you-fast-the-science-behind-it-all/)
The reason I’m asking is because whenever zone 2 training is mentioned, this seems to be the main selling point. If, however, fat oxidation is not very important for the outcome of the types of races I focus on, wouldn’t that to a certain degree steer my base training towards tempo and sweet spot that is way more reliant on glycogen?