What happened in this workout...or, why it's hard to train with HR

After reading some of the thread regarding new ‘endurance’ workouts in the TR workout library…and seeing @The_Cog muse that they might not provide sufficient training stimulus to impact adaptation…I though, hey, I’m kind of an expert on ineffective training strategies (that’s just my game) so I should give them a try. Check out the heart rate response…over the course of a couple hours it goes down, down, down.

During this ride, I consumed 100mg of caffeine. The ambient temp (according to Garmin) went from jitting back & forth between 77F & 78F to 84F. Heart rate by interval was:

Interval 1…122
Interval 2…115
Interval 3…112

What’s up with that? Why is HR trending down? Any opinions?

I’m no expert but I think If you are not doing enough to generate cardiac drift HR will drop over time.


I see this semi regularly on easy runs and bike seasons where the first interval starts without a (real) warm up, if you had the rest interval before the first work rep (interval) I think you HR would have been flatish.

Trait of no or an inadequate warmup. The body becomes more efficient once you get the engine running, you can then put out the same pace or power at a lower HR


Power data looks like its from the trainer (not power meter with power match).
In addition to the physiological explanations given above, I would be suspecting the trainer power accuracy changing over time. My Kickr power drops over a long workout like this, which is why I use power match.


Cadence looks marginally lower later in the ride. That’d account for a couple of bpm.


What ride did you do yesterday? All the recovery in this endurance ride could be aiding with recovery from a harder ride the day before. :grin:

eventually the caffeine activated leg muscle pump, providing assistance to the heart and thereby lowering your heart rate :rofl: Just playing the Monday morning quarterback game of spin the ExFiz-podcast-phrases :game_die: :game_die: And I’m not sure you proved the point of training by HR, although in general I agree with ya because it should be “use RPE, power, and HR to inform your training”

I’m sure that’s it!

But, nah, the whole point of the ride was just to shake down nutrition/hydration on the bike. So I was watching an event on TV while trying to execute my hydration/nutrition plan (everything on the bike or in jersey pockets).

The real story is I started this ride marginally hydrated and finished this ride well hydrated.

And totally jacked up on caffeine, of course, but well hydrated.


:muscle: :leg: :arrow_up: = :heart: :arrow_down: for the win! :rofl:

So much more satisfying than :potable_water: :arrow_up: = :heart: :arrow_down:

Negative decoupling is normal for me during indoor endurance rides. My takeaway is that it’s just the body slowly warming up and adjusting to the moderate load. It also supports my theory that LT1&2 are moving targets.

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@jonnyknight that is crazy! Thanks for sharing. Here is the Power/HR chart for my workout…can you share the Power/HR curve for the above workout?

I see similar neg DC with my regular 3 hour trainer rides. Here is just one example:


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Same here but OUTSIDE workouts

I stopped looking at decoupling a long time ago, except after coming of 2-4 week breaks.

Stupid steady eddy tricks outside!

Make it spicy :hot_pepper: and prosper!

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Sorry I can’t help myself, yesterday’s spicy endurance ride cut short

All HR zone1 and zone2 except for 15seconds at HR-z3. Some accelerated breathing here and there, no biggie, it was still pretty chill.

Now that’s a decoupling chart I can appreciate! The “you destroyed z2 ride benefit” crowd be all like :scream: in horror!

TR’s ‘Form Sprints’ :+1:

NOT form sprints.

If you are going to use TR terms, they were a combination of strength and power. Not structured, done in response to the terrain. And there were a lot of them, during an Endurance workout. Plus all the excursions into zone3.

Spicy endurance.

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I’m not being serious but if TR has sprints weaved in to their Z2 workouts they can’t think they are that bad :+1: Certainly not :scream:

the “you destroyed the z2 benefit” snarky comment was a reference to Inigo San Millan appearance on a podcast.


Dang that’s a lot of consistency. I don’t know if its me or the roads near me, but I can’t seem to get it that even outdoors. Here’s my solo endurance ride from last Wednesday

Been a minute since I did any solo work like this, so was pleased I could do the zone adherence this well on rolling terrain. Maybe I should take my piss poor average power/speed data over to the ‘new Z2 workouts’ thread :rofl: