Hello! Just noticed a trend over time that I thought I could pitch to the forum to ask about. I noticed that when go for a z2 ride, my heart rate tends to trend downward over time the longer I go. When I start my effort, my HR rises normally but as the time ticks up to 1-2 hours, I notice my HR dr…

I think that if you are aerobically fit you should not expect to see HR drift over a reasonable (<4hr) Z2 ride. I experience the same downward drift as you, especially inside where cognitive load, bike handling, weather, traffic, etc are a non-issue.

Assuming that’s Z2 power you are riding to? Z2 is a pretty wide range 56% - 75% so are you riding at a constant 70% or is your power dropping? Is this indoors or out? If out then environmental factors play a big part, there may be a slight wind that you don’t really notice but for the later part of …

I also noticed this during a long SS workout today, tried to screenshot it below. You can see my average HR was lower on the last two 20’ sets. [image]

A picture of an actual ride would help. One thing I’ve done to improve analysis of decoupling - ignore the first 30-45 minutes. You really want the analysis done with: steady state data AFTER you’ve properly warmed up at constant power output at constant cadence same body position same temperatur…

I also have the same thing sometimes, I just claim it as a long warmup.

For my self on a steady state Z2 ride I would expect my HR to be pretty flat and not drift much and perhaps even drift down over time once I’m settled down and moving efficiently. As the intensity goes up though I’ll see some larger drifts upwards.

That’s quite usual for me when the power goes down slightly as it is in your workout. Nice power figures btw :muscle:

Random Heart Rate Drift question

Training

akupecz December 15, 2020, 8:29pm 4

Think you are seeing negative aerobic decoupling. I have the same and it’s discussed here on the TR forum and see Google.

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