[Christian]

Hello everone,

I am currently experimenting with the heart rate drift test and repeatedly observe negative drift depending on the pace I pick.

I’d like to reach out to the community to find people who have observed similar patterns. So if you have experience with negative drift, if you know something about it or want to share your thoughts on the topic, let me know – I am curious to learn. 🙂

Currently, I have some hypotheses in my mind:

1. Is it still a warm-up effect? I do 20min warm-up before the actual test, so this would imply my aerobic system needs 50-60 minutes to warm up.
2. Is it a relaxation effect? The slow walks are really really slow and I find them quite relaxing. Maybe that triggers my parasympathetic nervous system and calms my heart rate.
3. Is it a suppressed heart rate effect? I observed that after a day of low heart rate training the next morning my resting heart rate is often a few beats lower. Maybe this suppressed heart rate effect starts right during training.
4. Is it a vaccuum cleaner effect? I definitely overtrained in the past, did too much high intensity, have ADS and no base. So maybe my body is in a glycolytic state even when I am doing nothing and maybe this slow walking makes the slow twitch fibers remove lactate. The analogy that triggered this idea: As I understand it, if you run to fast, you must slow down until the slow twitch fibers have used up the lactate and the H3O+ concentration has decreased before you can run fast again – so it seems as if you were getting fitter during this recovery period of slow running.

As soon as I have regained some fitness I will try to walk infinitely many rounds for various paces to see where these lines converge. It cannot decrease forever, can it? 🙂

Looking forward to your thoughts!
Christian

[Shashi Shanbhag]

The max heart rate I see is for Test 5 at 109 bpm. In this test is 109 your target heart rate at the end of your warm-up?

 

[Christian]

Hi Sashi,

thank you for your reply and for you question!
What is my target heart rate in these tests? It’s a whole journey! 😉

Test 1: Shot in the dark
Warming up to 95bpm and holding it. Negative drift. => Let’s aim for 100bpm next time.
Test 2: Strange result
Tried warming up to 100bpm, but 90bpm felt fast already, so keeping 90bpm instead. Negative Drift. But lower HR at a faster pace? => Try again.
Test 3: Serious doubt
Warming up to 100bpm and keeping it. Negative drift. But higher HR and lower pace? => How valid can this drift test thing actually be? Let’s challenge its reproducibility.
Test 4&5: Challenging the test
Warm up to lap duration of 80s and keeping the HR that stabilizes at that speed. => The connection between pace and drift seems to be reproducible.
Test 6: Finding AeT pace
Warm up to a lap duration of 55s and keeping the HR that stabilizes at that speed. Slightly negative drift remaining. => My AeT pace seems to be a bit higher.

My conclusions from this testing journey
– The connection between pace and drift seems strong and reliable.
– Drift does not have a reproducible connection with HR. (Thanks to Scott’s Tuesday Training Tip I now know that I wasn’t recovered for test 2.)
– I now train by pace whenever possible to avoid the risk of going too fast (like in test 2).

[Christian]

But to keep the forum thread on topic:
Do other people also experience negative drift if they go really slow? Or is it just some of us? And what would this tell us about our physiology?

Positive drift makes complete sense, but negative drift feels counterintuitive. I am curious to find people that know something about it or have made similar observations during their training. Maybe together we can solve the puzzle and understand where it comes from and what it means. 🙂

[Mark Postle]

My guess is these paces are so far below your actual Aet that you’re just seeing the results of being finally warmed up and your body being more efficient over time.  (it takes forever to warm up at sub 100 bpm HRs).  Most of our athletes target something around 180-age for their initial drift as an AeT estimate if they don’t have any previous data to lean on.

[Christian]

Hi Mark,

thank you very much for your response and for bringing your expertise to the conversation!  🙂 I got a bit cautious with heart rates because unfortunately I drove myself into overtraining using the MAF-formula and I observed positive drift at a rate of 90bpm already. But you are right, at the moment I am quite slow. If I guess my AeT at 50 s/lap, then 80s/lap would be 50% below my AeT and therefore I might indeed be just seeing a warm-up effect.

Your input inspired me to plan some slow drift tests without warming up to better understand the dynamics of the warm-up phase. At some point the negative drift must come to rest. Maybe I can find out how long it takes me to warm up at certain speeds. It is so exciting to understand and feel your own physiological state. I will keep experimenting and I’ll keep you posted! 🙂

 

[Christian]

Hi Mark, hi everyone,

since my last post I collected some more data. And as promised I want to keep you posted.

More and more I come to believe that there are two sources of negative HR-drift. The first is the warm-up effect you mentioned, Mark, for really low intensities. And the second is not being recovered and having to walk progressively faster to get and keep my HR up. In the second case I observe that I have to go faster and faster to keep my HR up and then I kind of “bounce back” and experience pronounced positive drift a little later.

[Brian Bauer]

what is your MAF number? i.e 180-age?  when you slowly jog for 1 mile, what is your average HR?  how much are you exercising per week? run volume, bike volume, walking, etc? do you consider yourself to be healthy with some fitness? even with all of the data you are sharing, without knowing something about you, its not possible to offer an opinion on your negative drift question.

[Christian]

Hi Brian,

thank you very much for your reply! You are absolutely right, lots of context is missing and I am completely aware of it. The reason is that I do not want to make this a personal thread about me (I think this would belong in a private coaching session). I rather wanted to reach out to the evoke endurance community, share my experiences with negative drift and maybe find people that made similar observations.

My last post was meant to share what I found out, namely that I see a linear negative drift for slow paces and a kind of negative logarithm shape when I am not recovered. And if I go too fast, my drift is positive of course.

Have you ever observed negative heart rate drift in your training?

Kind regards
Christian

 

[Brian Bauer]

it is not unusual for me to discover in my data that in the later stages of a 2-3hr race I am moving much faster at the same HR.  if I kept the pace the same this would show a declining HR over time.  However, my intent is normally to remain at a Racing level of effort which results in greater speed not a reduced HR.  in my case this is caused by a lactic shuttle that improves over race duration

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