Visualizing HR, HRV, and GSR While Watching ‘Interstellar’

Interstellar

(Note: This experiment was inspired by a Reddit user who recently posted a graph showing their heart rate while watching the movie Interstellar).

Last week I went to see Interstellar (in IMAX, for full sensory effect!) and captured some biometric data to see how I reacted during the course of this nearly 3-hour movie. I wore a Polar H7 heart rate monitor paired with the SweetBeatLife app on my iPhone, along with my wrist-worn Basis B1. I exported the raw data from SweetBeatLife using their built-in export tool, and my Basis data using my Basis data export script.

Whereas the original experimenter only tracked heart rate, I wanted to analyze:

  • Heart Rate
  • Heart Rate Variability (HRV)
  • Galvanic Skin Response (GSR)

Heart Rate

Interestingly, my heart rate trend (on the left, below) looks very similar to the original Reddit user (on the right)! Both of us are using data from our wrist-worn Basis devices – in my case, the older B1 model, and for the Reddit user the newer Basis Peak. Although the Peak is capable of capturing more samples, the data returned from Basis is always an average value for each minute.

Interstellar HR comparison

However, SweetBeatLife is recording data at a resolution of 1 sample per second via the Polar H7. The per-second pulse data is a little bit jumpy and hard to follow (in gray), so I’ll also include a 60-second moving average as well (in blue):

Interstellar Heart Rate Polar H7

It looks very similar to the data recorded by my Basis. Good!

Heart Rate Variability (HRV)

Heart Rate Variability uses a technique in which the spaces between heart beats are measured, and is a good way to measure stress via an individual’s “flight or fight” response (the higher one’s HRV, the better). There are a number of ways HRV can be calculated, and in this case we are using what’s known as rMSSD (root mean square of successive differences). You can check out Wikipedia for a pretty good overview of HRV.

Interstellar Heart Rate Variability

Galvanic Skin Response (GSR)

Galvanic skin response (also known as skin conductance) can be used as an indication of psychological or physiological arousal:

Interstellar Galvanic Skin Response

My GSR started out rather elevated, which I guess was due to a combination of anticipation for the movie to begin as well as my eyes getting adjusted to the huge IMAX screen (and my body adjusting to the temperature in the theater). I was clearly into whatever was happening on-screen between 1:50 and 2:20!

Putting It All Together…

Now, if we look at all of the visualizations together, we can easily spot key moments in the movie (no spoiler alerts here, but if you’ve seen the movie you should be able to figure out what was happening in each area!), or when I might be internalizing some deep analysis of gravity and multidimensional spacetime, or simply bored (the movie takes some time to really get going!). We can also see when my stress response kicks in or relaxes (phew!).

Interstellar HR HRV GSR

Looking back at the data, you’ll see there is often an inverse relationship between heart rate and HRV, which makes sense – if your heart starts beating faster, you are most likely encountering more stress, which increases your sympathetic response and thus lowers HRV. Galvanic skin response typically is reflective of one’s sympathetic autonomic nervous system response (will increase as HRV decreases).

I think a great experiment idea would be for a bunch of self-quantifiers to all go see the same movie so we can all share and compare our data! Shoot me an email if you’d like to get involved.

Mobile Health and Telemedicine App Test Drive

I began to virtualize the way I manage my health several years back with the launch of ZocDoc, which provides an online system to locate and schedule appointments with doctors (similar to the way we use OpenTable for restaurant reservations). Flash forward to today, and my functional medicine doctor lives almost 2000 miles away. We keep in regular contact through email and set up monthly 30 minute consults over Skype (we do meet face-to-face at least once a year). He has access to all of my lab data in addition to other QS-related data I provide (there’s a misconception that the quantified self movement is “anti-doctor”, which is not the case – the issue is finding the right doctor(s)).

But things are just getting started. A number of mobile health/telemedicine-related technologies are coming to market that will continue to disrupt healthcare – by not just saving time and money, but potentially saving lives and allowing patients to have access to the best doctors regardless of geography. Dr. Eric Topol talks about the impending democratization of health care based 8 key consumer drivers: sensors, labs, imaging, physical exams, access to medical records, transparency of costs, and digital pills.

Here are a few examples of mobile health apps I have recently used:

[Read more…]

Bulletproof Diet and Intermittent Fasting – My 1.5 Year Results

tl;dr version:

  • The Bulletproof diet has worked! (for me, at least). But it’s less of a “diet”, and more of a lifestyle.
  • To follow the diet long-term, some individual refinements need to be made (such as cutting back intermittent fasting, increasing carbs or adding a “refuel” day, or avoiding certain foods until pre-existing gut/autoimmune issues have been addressed).
  • Out of range markers such as high LDL cholesterol were not due to the diet – rather, the diet “exposed” other pre-existing issues such as under active thyroid and adrenals, gut issues, and chronic infections. 

Background

It’s been a little over a year and a half since I decided to try out the “Bulletproof Diet“. In earlier posts (which I highly recommend skimming in order to get some background/context), I provided an overview of the Bulletproof Diet as well as recaps before and after my first 30 days:

What is the “Bulletproof Diet”?

Bulletproof Diet LogoTaking many queues from the popular Paleo/caveman diet, the Bulletproof Diet could be called an “upgraded”/Paleo 2.0 diet. The premise is simple – eat a high (healthy!)-fat, low carb diet, getting 50-70% of calories from healthy fats, 20% from protein, and the rest from vegetables (with some fruits and starches). A major difference between Bulletproof and Paleo is the attempt to minimize toxins from the diet which are thought to play a major factor in everything from inflammation to “brain fog”.

By sticking to approved/”bulletproof” foods, you avoid/minimize eating things that can make you weak and fat, replacing them with high-quality foods that fill you up, maintain strength, and even enhance cognitive efficiency.

Bulletproof Diet Infographic

(Download a full version of this graphic for free here.)

Intermittent Fasting

The Bulletproof diet also incorporates intermittent fasting, whereby you consume most of your calories during a very small window, typically 6 hours and fast the remainder of the day. In other words, you would eat all of your meals between, say, 2pm and 8pm. By restricting carbohydrates, your body goes into ketosis, and starts to use fat as it’s primary source of energy instead of glucose. You can learn all about intermittent fasting at Leangains.com.

Note: If you have any adrenal/thyroid issues, read further down as you may want to minimize/stop intermittent fasting until those issues are resolved.

Bulletproof CoffeeBulletproof Coffee

A staple of the Bulletproof diet is a magical concoction called… wait for it… “Bulletproof Coffee”. In fact, most people seem to come across the coffee first, then discover the diet. You get to “cheat” intermittent fasting by having a few cups of Bulletproof coffee in the morning – a combination of high-quality, single-origin, mold-free coffee beans with grass-fed butter and MCT (or coconut) oil, which does wonders to stave off hunger while increasing cognitive function over the final few hours of your fast.

My 1.5-Year Results

When I originally sat down to put together this update, It was closer to being my 1-year anniversary, but I decided to hold off on posting anything until I was able to address a number of issues (thyroid/adrenals, gut/autoimmune issues) that were uncovered over time (more details to follow).

[Read more…]

Ten Things I Learned at the 2014 Quantified Self Europe Conference

QuantifiedSelf Europe 2014On May 10th-11th 2014 I had the pleasure of attending (and speaking) at the 2014 Quantified Self Europe conference in Amsterdam. I have attended the annual US conferences the past few years, so I was excited to see lots of familiar faces, and even more new ones. It was a fun, educational, and inspiring time and my post-event buzz still hasn’t worn off (whereas thankfully the Jenever has!).

In the spirit of Quantified Self’s “Show and Tell” talks, I’ve structured my recap using the 3 questions every presenter is required to answer…

What Did I Do?
I attended Quantified Self Europe 2014.

How Did I Do It?
I registered for the conference, prepared my talk, and eagerly got on a plane from New York City to Amsterdam, where I took a short train ride to get to Hotel Casa 400.

What Did I Learn?

1. So many great sessions (and not enough time!)

The conference was so packed full of great talks and breakout sessions happening at the same time that there was simply no way to see it all. Fortunately, most of the talks (including mine!) were recorded and the QS folks will be posting videos shortly. I often found myself running from room to room to take in as much as possible or walking in late because of a great conversation I was having during one of the breaks!

Quantified Self Europe 2014 Breakout

credit: @addappio

2. Privacy concerns shifting from “mine” to “yours”.

Whereas the QS privacy/data debate has focused on the self, there was a much more awareness about factoring in the privacy of others we may be recording without their consent/knowledge with the proliferation of “lifelogging” devices. And even with all of this lifelogging going on, ironically, not one person posted a photo of me giving my talk on the conference Flickr stream! (please send me a pic if you took one :))

Narrative Clip

credit: Jim Tuttle/NPR

3. Europeans have a much better fashion sense than Americans.

Amazingly, I did not see one person wearing a pair of Vibram Five Fingers. Sorry San Francisco!

QS-shoes

credit: Rajiv Mehta

4. QS is not just about health.

While much of the QS subject matter has a heavy focus on health/wellness, people are using self-tracking to better understand all aspects of their lives, from productivity to grief, improving memory to goal setting, improving relationships to tracking media consumption, to even transforming data into art!

Quantified Self Data as Art

credit: @kiranezu

5. But as it relates to health, QS…

Is evolving from people sharing stories about identifying/treating/overcoming existing problems to using self-tracking as a way to take proactive/preventative measures to ensure they can live optimally both today and in the future (what’s the point of living a long life if you aren’t able to truly “live”?).

Quantified Self Europe 2014 Fitness

credit: @yago1

6. Quantified Self vs. Biohacking

While QS and biohacking are very connected, not all QSers are biohackers, and not all biohackers consider themselves QS practitioners. This seems to be becoming more evident as practitioners begin to push the envelop on both fronts. I personally view myself as someone that falls smack in the middle – an avid practitioner of both.

Quantified Self vs. Biohacking

7. QS is a global movement.

Probably my favorite part of the conference was that as an American, I was of the minority in attendance, and it was great to engage with so many people from other parts of the world. They really brought a fresh perspective to the QS conversation. That being said, as much as I love San Francisco, I think future QS conferences would benefit from moving to locations outside of the San Francisco/Bay area, where it can feel very insular and disconnected at times.

8. Startups, startups, startups.

As the QS movement continues to grow, so too is the QS-related startup ecosystem. It was great to see companies that just a year or two ago were nothing more than a prototype finally launching and raising some serious capital. In addition, some big established companies are beginning to show up (from consumer electronics to pharma). I hope that future conferences can maintain their content focus on allowing individuals to give talks about their personal journeys and not having the talks get too commercial/salesy (I will still visit all of the sponsor booths!).

Quantified Self Europe 2014 Sponsors

9. Seth Roberts left a lasting QS legacy.

The closing plenary was a touching tribute to the late Seth Roberts, who unexpectedly passed away just weeks before the event. While I never knew Seth personally, I definitely admired and have been inspired by his work and it was touching to hear various attendees share their stories about him. Whether you are simply curious about self-tracking or are an active practitioner, his blog and papers are required reading.

10. Amsterdam is an awesome city!

After spending 2 rainy days holed up in the conference hotel, I was so glad I tacked on a few extra days after the conference to check out as much of the city as possible. If you’ve never visited, I highly recommend it. It’s the most laid-back, friendly city I have ever been to. I can’t wait to go back!

blt-amsterdam

Thanks again to all of the conference organizers for putting on such a great, smoothly run event. I realize what a tremendous amount of work must have gone into making it a success! The QS folks have posted their own recap/roundup, which also includes links to recap posts by other attendees. Can’t wait until the next one!

 

Hacking (and Tracking) My Glucose

I never paid much attention to my blood sugar (aka blood glucose, or as I will simply refer to it, glucose) until a few years back, when I started getting more interested in self-tracking/biohacking and my 23andMe DNA analysis showed that I had a genetically elevated risk for type 2 diabetes, which has been shown to be preventable by maintaining low levels of glucose. Elevated glucose can also contribute to a number of other health issues such as cardiovascular disease.

23andMeType 2 Diabetes

The current “accepted” recommendations by the American Diabetes Association for fasting glucose (i.e., no food or drink in the previous 8 hours) are between 70 – 130(!) mg/dL. The exclamation(!) mark is there for a reason. The upper bound is being hotly disputed – in fact, the ADA has a term called “impaired fasting glucose” that was lowered from 110mg/dL to 100mg/dL in 2003. That means that many people that are classified as “normal” are, in fact, pre-diabetic. Organizations like the Life Extension Foundation (a leading organization focused on advancing research on longevity and anti-aging) suggest keeping fasting glucose at or below 85 mg/dL (and optimally even below 80!).

My most recent blood test showed my fasting glucose level was 85mg/dL, considered “good”, even by Life Extension Foundation guidelines. But what I wanted was to better understand how various factors affected my levels, and then be able to proactively control them. Even though my glucose is considered good, I wanted it to be optimal. Why take any chances? [Read more…]