Some Help Understanding Fasted Training Recommendations

So, I am trying to understand different things (mostly things I have heard on the Ask a Cycling Coach Podcast) about fasted training. Here’s what I have heard:

  1. You have glycogen stores for about 70-90 minutes of training.
  2. “Easy” aerobic efforts largely utilize oxygen and fat metabolism for fuel.
  3. Don’t do anaerobic workouts in a fasted state.
  4. Don’t do fasted training on workouts longer than 90 minutes.


a. If 1. and 2. are true, why shouldn’t I do more than 90 minutes of fasted training at an easy level?
b. If 1. is true, shouldn’t most mid-volume workouts under 90 minutes be okay in a fasted state even if they have anaerobic components and sweetspot/threshold work? (As long as I use adequate recovery nutrition? I realize that those workouts won’t increase fat metabolism, but this is mostly about eating early in the morning or too close to the workout).

Can anybody help me make sense of this? Specifically, I am currently starting SSB2 (mid-volume) and my Thursday schedule makes eating before workouts really inconvenient. I have tried the half-hour high-glycemic thing last season, but I don’t really like it.

Hey @cyclhist - I think you’ll get a multitude of feedback on this, and I hope you get the advice you need. It seems to me like you are simply asking about fasted training because you can’t eat before a workout, right? So no aims to drop weight etc?
Have you considered drinking something with carbs in throughout your training, so that you are getting the best out of your sessions? I find that can help with maintaining an energy balance, especially if you have a full day of work ahead of you.
I have no problem with a 90 min fasted workout, but I have adapted to that over the years of training!!

My personal recommendation (n=1, YMMV, etc.) is that fasted endurance rides longer than 90 minutes are both very reasonable and helpful over time to elicit training adaptations.

There are a couple of other good live threads on the subject::

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