Fasted training – Increased heart rate

  • Creator
  • #47591

    Hi Guys,

    I am new to the forum but have been following the topics and The UA books for some time now. Great job, first and foremost!

    However, I have recently experimented with fasted Zone 1 – training. My observation is that my heart rate in these workouts (I did 4 of them so far) is much higher than in an unfasted state, or, respectively, at comparable heart rates my pace is much lower. The effect is immense and accounts to about 25 %.
    I have searched the forum but could not find anything related to this.

    Does anyone have an explanation for that?

    More importantly, if I want to do Zone 1 – workouts in a fasted state, how should I handle this? If my pace in these is so much lower, I am scared I am actually not doing anything other than recovery pace (or not even that)? Eventually the difference vanishes as soon as my body gets more accustomed to fasted training?

    Really looking forward to your responses,

    Love from the austrian alps,


  • Participant
    Rachel on #47731

    It will improve for sure, your body will adapt. For the most part I don’t notice a noticeable difference now with fasted vs non-fasted Z1 and Z2 workouts with one big exception: if I cut carbs from my diet I get that HR spike again.

    Take this morning. I cut virtually all carbs out starting Monday (I’m doing the Maffettone carb intolerance test, which is almost keto) and did a 6 mile fasted Z2 workout. So I was pretty much completely glycogen deprived. It was painfully slow and my HR spiked easily, I had to stop a ton going uphill, whereas usually I can keep chugging along. I noticed I was breathing harder and my leg muscles would even feel it on occasion which I hadn’t noticed before.

    I figure it’s the price to pay to become better at fat burning.

    pezrosi on #47742

    Thanks a lot!

    Glycogen deprivation does not seem to be the issue in my case as i am on a rather high-carb diet!

Viewing 2 replies - 1 through 2 (of 2 total)
  • You must be logged in to reply to this topic.