Category Archives: parasympathetic flatline

Heart Rate Belts, Phone Cameras and Convenience

I had a chance to have a coffee with Marco Altini, the builder of the Heart Rate Variability Logger app that I often use to take readings. I enjoyed the discussion as Marco is very knowledgeable on the topic of heart rate variability. I took some key insights away that will help me set direction for future studies.

During the discussion he told me he is focussing on his app that support physical training, HRV4Training. He prefers to work on this because in addition to a bluetooth heart rate belt the user can choose to take a reading with the camera on the phone. Marco thinks that the convenience of using the camera makes it more accessible.

I agree with him. In my own work I often to not take advantage of readings because I don’t have the belt on and simply don’t feel like putting it on. Just this week I did one reading while conducting an interview using the belt, and I did not take readings on numerous meetings that would have given me good data for further study.

And while pushing into new areas of study such as heart rate variability during negotiations, or while giving a speech, it is not going to work to have a finger on a smart phone camera. To only use the camera would confine readings to stationary sessions where no activity was allowed. There is much more to learn than taking readings in only a motionless state.

So I am going to start incorporating smart phone camera useage into my work and share the results here. Marco has done a workup of how his apps use the camera to compare well with the Polar H7. We have to figure out a way to make this accessible, and useful, so more people can train for improved personal performance using heart rate variability.

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Five Meeting Heart Rate Variability Compared

I had an opportunity to compare five meetings that had similar content and the same attendees over a one month period. My colleagues and I were preparing a big launch and we were looking at the plan in a series of review meetings. In the first meeting I had created a first draft plan and had to present to executives I was meeting for the first time. I was not sure of how they liked to consume information and was on edge. So the first meeting looked like this:


What you see here is that I was in “overdrive” 33.8% of the meeting time.Overdrive means I my parasympathetic nervous system had stepped aside and my sympathetic nervous system had me in fight/flight mode. The blue lines in the chart are those heartbeats where the difference in time between beats was under 17 milliseconds for at least 10 consecutive beats. This meeting was almost two hours long, I was answering a lot of detail and we were finding our way together so I was in overdrive for one third the time.

We returned to review the progress from the first meeting a week later. In this I had my materials memorized and I knew how the executives consumed information. The meeting went very well, and we still had a lot of work to do. Using the same definition of Overdrive here is the chart:


This second meeting was almost two hours long and because I was so prepared I was in Overdrive only 10.8% of the time. As you can see from the chart there were only periodic physiological accelerations. Big difference. In the next meeting, the executive I was supporting and I did not have a lot of time to prepare for the meeting. We went in without synchronizing. You can see the chart here:


I was in Overdrive 15.2% of the meeting. You can see that my physiological fight/flight lines are concentrated early in the meeting as the executive that I was supporting and I were synching up. We found our way pretty quickly and you can see the blue lines even out.

In the fourth meeting we had taken another week to make progress on the launch. A lot of the details were worked out and we were in pretty good shape. When we got together the same executives were in the room and my supervising executive and I had a chance to coordinate. You can see the results in this chart:

Overdrive was only 4.4% of the time and the meeting was smooth. I felt good in the meeting and the readings show things went smoothly. We had one last meeting to get final check off an approval. I would through this data out because the environmentals of the meeting completely threw things off. You can see the data is very different:


Here you see a complete physiological meltdown as I was in Overdrive 87.2% of the time. Turns out the office I was taking the meeting from was extremely hot. I was perspiring and uncomfortable. It was a distracting situation. The meeting went well. We got approval and the communications afterward were universally positive. I believe the physical discomfort overrode the comfort with the materials.

So it appeared that reviews of familiar material with the same team of people did results in less time in Overdrive. Comfort with the material and people improved my performance. The last meeting is odd and I can’t definitively explain it with the hot temperature. But the first four seem to indicate improvements.

Parasympathetic Flatline Talking versus Listening

I wanted to look at how often I entered the Parasympathetic Flatline while in a 1:1 conversation with a colleague by phone. For the discussion I read by heart beat intervals using a Polar H7 heart rate belt and the Heart Rate Variability Logger app for iOS. I also recorded my side of the meeting on a smart phone. When the meeting was complete I downloaded my heart beat intervals via csv file and pulled them into excel. Once in excel I used a formula mechanism I created that graphs segments where more than 10 consecutive interbeat intervals are less than 17 milliseconds apart.

During the 60 minutes session I measured 4,451 heart beats and the intervals between them. Of those intervals, 14% were in groups of consecutive intervals that were close together, meaning during 14% of the meeting I was in what I call Parasympathetic Flatline. This measured the periods where I was in fight/flight mode during the discussion.

Here is a vizualization of the meeting:


In the session the forty-seven stress events triggered. Of these, 22 of 47 occurred when I was talking and presenting information to my colleague. 25, or 53%, occurred when I was listening to my colleague.  When listening to the recording, it is clear that the stress event, even when occurring when I am talking, begin when I was no agreeing with my colleagues response or trying to move him to a different position. The stress response was a result of not liking the direction the conversation was going.

Again physiology has shown that anticipating and trying to shape another person’t response is the source of stress in a 1:1 interaction. I once thought presenting my own opinion was a source of stress but that has turned out not to be the case. The stress, it appears, is not agreeing with someone else presenting their opinion.

Added clarification: From Twitter, fellow QS’er Gustavo (@GGlusman) asked the percentage of time I was talking versus not. Pushed by the question I went back beat by beat and looked at the session. As I reported above 736 beats were “in stress ” meaning that those beats were in a grouping with more than ten beats that occurred with a difference in beat interval less in 17 milliseconds to the adjacent beat. Of those beats in stress, I found that 238 were while I was talking and the remainder while listening. So that means 38.5% of the stress beats occurred while I was talking, 61.5% while I was listening. Impatience while listening was clearly more stress creating than flapping my gums. Thanks to Gustavo for asking the clarifying question!