
What’s Your Heart-Rate Variability? It May Be Time to Find Out - fmihaila
https://www.wsj.com/articles/whats-your-heart-rate-variability-it-may-be-time-to-find-out-1498442460
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Pfhreak
I wear a heart rate monitor when I stream videogames, and wrote a simple
visualization sparkline/beating heart I could throw in as an overlay. I was
surprised at the variability of my HR in various situations, from lows of
around 60 to highs in the 140s.

Even in 'normal' parts of the gameplay when I wasn't under stress I'd see my
heart rate shifting all over the place. One moment of calm I'd be at 65, then
80, then 70. I started playing with it, to see if I could swing the needle
with breathing, and quickly found that gamifying it led to my heart rate
increasing when I was successful at decreasing it. (I'd get excited that I had
lowered the rate, which increased the rate.)

I was also surprised to learn that my heart rate spiked significantly _after_
tense moments in the game. In game combat usually didn't cause the rate to
rise until 30 seconds or so after the combat started. I felt the intensity and
the rush immediately, but the HR increased later.

I also found that games slowly lose their HR impact over time. A game like
Player Unknown's Battlegrounds could get my HR into the 120s pretty easily,
and now it only raises my HR into the 90s when it's tense.

It's fun to have access to all this data about ourselves, and I'm glad to see
so many different ways of using it -- from dialing in a few extra % on your
athletic goals to showing goofy SVGs over a videogame.

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registered99
Care to share the strap you used?

I've been looking for a while and it seems straps are all over the place in
terms of being easily accessed without proprietary adapters

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ocharles
I'd get something that supports ANT+ along with an ANT+ usb dongle.

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Pfhreak
That's what I am using, though finding a decent Ant+ library took a while.

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guelo
This article does not explain HRV very well. Would I be correct in thinking of
it as the volatility between beats? Or the erraticness between beats?

Let's say I have a heart rate of 60 bpm. And my beats are

    
    
      1 second -> .9 seconds -> 1.1 seconds
    

While another person also at 60bpm beats are

    
    
      2 seconds -> .5 seconds -> 1.5 seconds
    

then the second person has higher HRV and is stronger, more rested, more calm,
has more energy? It's strange to think that having more erratic heart beats is
better.

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clwk
Here's the thing: the way HRV is measured reliably when used as a metric is
with 'paced breathing'. You synchronize your inhalations and exhalations to a
displayed pace (in for X seconds, out for X seconds, or whatever).

The primary source of variability under those conditions seems to be that HR
increases when inhaling and decreases when exhaling. Seen in that light, it
makes more sense.

Essentially, what HRV may measure is ability to actively and acutely lower HR
(which is most naturally performed during exhalation). This is not so unlike
how some exercise equipment will provide a fitness measure based on heart-rate
recovery: how long does it take you to return to some percentage of your
resting heart rate after having exercised?

At this point, I'll make an analogy, which is meant only to be that. If you
have a high income, you can afford to spend a lot of money on a day-to-day-
basis. Depending on how you set things up, you might see a wild flux in bank
balance, and that's just fine -- because you can afford it.

Likewise, performance athletes experience highly-elevated heart rates
regularly. Indeed, it's that stress which leads to fitness adaptations. Just
as you need to spend money to make money, you need to stimulate the heart in
order to strengthen it. High HRV (as far as I can tell), may largely
correspond with the naturally-adapted ability to rapidly return to the calm,
low-HR state characteristic of the well-trained athlete.

When you live check-to-check, you have to budget very carefully and avoid
variability in spending. You can't afford to venture, and you don't gain. When
you know huge cash infusions are around every corner, you don't worry about
spending.

Likewise, the fit heart doesn't need to damp and suppress stimulus. Elevated
heart rate is _good_ (think about the positive moments in life which can cause
this), as long as it doesn't lead to chronic stress but instead evaporates in
the space of a breath or two.

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agumonkey
btw, I'm looking for ideas about breathing patterns. I've noticed blood
flowing differently[1] if I pause with fresh air in my lungs before releasing
it.

Some docs says that breathing influences arteries constriction (or the
opposite).

I wonder if it helps increasing oxygenation ..

[1] palms and feets get a tiny heat wave, also a sensation of relaxation in my
veins

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Nokinside
Polar heart rate monitors have measured heart-rate variability for decades and
used it to set the HR limits.

Polar uses R-R intervals to adjust heart rate high and low limits for for
exercise period (unless you set them manually). I think they are called
ownindex and ownzone.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4751190/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4751190/)

[http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100...](http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008001000004)

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yosito
It seems like a huge jump is being made from a hypothesis to interpretation of
data. Has the connection between HRV and the body's preparedness for exercise
been tested in repeated experiments?

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ars
See here: [http://www.thedailybeast.com/inside-seal-team-six-by-don-
man...](http://www.thedailybeast.com/inside-seal-team-six-by-don-mann-excerpt)

> Dr. Morgan also found that the metronomic [non variable] effect is often
> associated with early heart disease and even sudden death. Apparently, the
> body chemistry that allows young people to survive under high stress does
> not translate into optimal heart health past the age of fifty.

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ctvo
Is there an app for this yet? I wear an Apple Watch all day -- it'd be great
if something were available. Poll every 10 minutes for 30s or something to
conserve battery maybe.

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askafriend
Apple Watch already polls you every 5mins or so throughout the day. You can
use an app like Cardiogram to hook into the Apple Watch data to visualize nice
graphs and correlations.

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matt4077
HRV is defined as variability in the interval between individual heartbeats.
Pulse data with a 5min-granularity won't help.

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neves
It looks like there isn't a good fitness tracker to measure HRV. They aren't
precise enough. It would be necessary to use a chest strap. I don't believe
I'll be able to do it with my cheap Mi Band 2.

Does anybody here know about a good fitness tracker to measure HRV?

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neves
Do you recommend any Android app to measure HRV? I have an ANT+ band that I
connect to my phone.

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melling
Here’s a non—paywall story that discusses HRV:

[http://www.telegraph.co.uk/men/thinking-man/heart-rate-
varia...](http://www.telegraph.co.uk/men/thinking-man/heart-rate-variability-
testing-can-use-get-healthier/)

“heart rate variability is essentially the gap between heartbeats when you are
resting. A longer gap between heartbeats indicates you are well rested,
whereas a shorter gap could mean you are stressed out and running the risk of
overtraining”

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anbende
Seems like that quote misses the 'variability' bit. Gaps might be longer or
shorter, but it's how variable in length the gaps are that indicates HRV.

