15th century
21st century

Smart body

Marko Bogdanovic, summer 2019

The boom of quantified self movement - smart watches, health trackers and body sensors - is implicitly telling us that now at this point in history an average mortal can see into her body and learn about herself - thanks to these devices. They are miracles of the 21st century. They feed our curiosity.


- “Oura shows your average respiratory rate from each night.” - Oura (it's a ring on finger)

- “It [smartwatch] also tracks your heart rate variability, which is used to calculate and display your stress level [...]” (Garmin vívosport)

- “With the heart rate data it collects, vívosport is able to estimate your VO2 max and fitness age, 2 indicators of physical fitness [...]”

- Wi-Fi scale Withings Body+ estimates percentage of fat mass, muscle mass, water and bone mass.

One of the outcomes of smart devices with body sensors and all the derived insights – an outcome that is very hidden in my opinion – is that we will further numb perception skills that we already have, "in-built". These were carved by hundreds of thousands of years of evolution and by buying into these smart devices too fast now, just because of clever marketing, peer pressure and laziness of human brains, we loose contact with our very own selves more and more. That is sad and unnecessary.

But do I really need to have insights about some body activity in numbers with precision of two decimal points? Or do I really need to know that today I walked 5502 steps and yesterday it was 7349 steps? Why exactly do I need such precision?

Suppose this scenario: There are no smartphones in the world. You like to go running, your brother likes to go running. You only have 6 degrees of expression of how much you can run – they are called "1", "2", "3" and so on. Let's say that your brother “ran 4” for last five days and you also “ran 4” for last five days. Because you cannot compare just by number themselves, is that really a point where you loose motivation to run? At least this is what's always cited as main reason for turning things into competition with close friends – motivation and being fit. You “ran 4” for 5 days - aren't you feeling fit? The downside of this hypothetical world is that the gym statistics are a bit boring for some of us.

Could it be enough to just know about some bodily activity on such scale of 6 degrees? In life-critical situations in hospitals for example it would not, but in other situations – which form majority of consumer market – it can definitely be enough in my opinion. There is very little need to succumb confidence in ourselves to trends created by the marketing of big companies.

I want to try to convince you in this text that you can learn some ways to feel how your body is doing in regard to what interests you. You definitely cannot learn about as many things as all those devices combined allow you, but at least some points will convince you - I hope - to cultivate or re-awaken your senses, put hi-tech aside (sealed in basement) and be in fulfilling contact with your self and your life. The point is to restore your confidence in yourself.

It will be fun - a bit unusual one though - I promise.

Gear under the hood

You probably think that humans have 5 senses. That's what Aristotle came up with 2300 years ago and we (at least in western culture) did not properly update that. Why? Maybe because it's easier for our minds to deal with concept of 5 senses instead of 17 or more. What's so difficult about it when a European can count 28 member states of EU (and know the basic differences and similarities) and USA citizen can in average case count his 50 states?

Can you count your 30 personal belongings? Could you count your 20 senses?

One part of the 5-senses problem is scientific definitions. While scientists and philosophers argue, everyone is left with pretty outdated and limited mindset about what they are able to percieve and consider. I dare to say that moving on without waiting 30 years for the resolution of definitions is going to give us an advantage.

Some less heard-of human senses include:

balance and acceleration

sense of body position and movement (proprioception)

temperature sensing



thirst (salt concentration in blood)

chemoreceptors for CO2/O2 levels in brain

lungs stretch receptors

digestive tract stretch receptors

studies are trying to see if humans too can sense Earth's magnetic field and results are surprising[1]

few more types of perception that aren't based on specific organ:

time perception



Quest for survival

Our skills didn't come as some kind of present down from skies. They were hard earned and kept sharp via thousands of years of ongoing evolution. Tens and hundreds of thousands actually. And word evolution is just an euphemism for what essentially is a pretty rough fight for survival.

Dangerous animals

Before last ice age ended 12 000 years ago, large parts of Europe and North America were covered by thick ice layer and dense forests. In film Cave of Forgotten Dreams Herzog says that Europe was covered by 2 kilometers thick ice layer. Earth was roamed by many large animals, that we had to hide from, run away from or hunt down. Plus we had to find some 'easier' food mean-while.

It is not only about saber-toothed cats, bears, wolves etcetera. You have probably seen some lions-hunt-zebra scenes in nature documentaries. But have you ever thought of how well can the usual pray fight back? Go to Youtube and search for “buffalo attacks lion”, moose attack, elk attack and similar videos. Or have you ever seen any bull fight videos or rodeos? Why do those hundreds-of-kilos-big animals have those long hard pointy sharp things growing from their faces or heads? All of these are champions of evolution! And we were surrounded by them for millennia.

Have a look at film Quest for Fire by Jean-Jaques Annaud, Werner Herzog's Cave of Forgotten Dreams or Grizzly Man. Or film Jane about Jane Goodall – there you can see quite some scenes of chimpanzee aggression. Seeing these films can help you get the feeling of how it might have been to be alive at those times.

Or – what works well but is a very mild version of all this: if you have never done it, stand alone for couple of minutes at the edge of a forrest after it gets dark at night. How does it feel? Do you want go in?

Can I eat this?

How many tree species can you recognize with certainty? Can you do more than 15?

How about food – imagine it's autumn many thousands of years ago, you're alone, you have not eaten for a day or two and at the edge of the forrest you find these berries. Can you eat them?

6 pictures of different wild berries
image credits: 1) farafina - needpix/pixabay.com, 2) Bob Richmond - Phytolacca americana Knoxville TN, 3) Dladek - Vaccinium corymbosum 'Polaris', 4) VoDeTan2 - Prunus laurocerasus macrophylla, 5) Albert Bridge - Berries, Lisburn, 6) Hans (22726 kuvaa) from Pixabay

I am trying to trick you into positive judgement by choosing pictures that look like taken in a garden but truth is mostly negative. Our ancestors were able to recognize which of things they found would kill them, which ones would feed them or which ones could be used as a medicine. How do these berries smell if open? Is it a bit too bitter? Maybe it's just not ripe enough but it's still okay. Or is it outright poisonous?

Here's an excerpt from from Micheal Pollan's book How to change your mind. In one chapter he describes how he tried to learn for several days to distinguish a specific sub-specie of mushrooms before he and a scientist went to search for them in a forrest:

“We found seven azzies [a specie of psychedelic mushroom] that afternoon, though by we I mean Stamets; I only found one, and even then I wasn’t at all certain it was a Psilocybe until Stamets gave me a smile and a thumbs-up. I could swear it looked exactly like half a dozen other species I was finding.”

Maybe you have heard news about people poisoning themselves by eating wrong mushrooms. 23 species of primates (including humans) consume mushrooms – that means that they are able to recognize “good” from “bad” ones. Our ancestors were able to do it too because their senses and brain were sharp.[2]

Anyway as an example of today's sharp skills, it seems that Paul Stamets is doing quite well as mushroom specie 'recognizer'.

We, humans as well as al other animals, had to put all our skills to use to be able to make it through each day. And our senses had to be pretty darn sharp or it cost us life. With every new berry found, with every strange smell or sound coming with the wind.

My personal experiments and observations

With arm of choice and eyes closed, touch your knee on the leg opposite of the arm.

Make variations with shoulder, toe, hip, etc. Isn't it quite interesting that we can do this? My usual error is only around 1-2 centimeters. Proprioception is the name of the sense that enables us to do this.

Estimating my body temperature when I was sick as teenager

I used to be sick as teenager roughly twice a year. I would spend a week in bed, watching TV, taking some pills, drink hot tea, sweat and slowly get better.

My parents were at those times always very into measuring my temperature few times a day to see how I'm doing. I remember one of last years when I was sick: I was guessing the temperature that thermometer will show when the time comes to take it out of my armpit – just based on how well or not so well I felt at the very moment.

I was very amused and puzzled by how very accurate I was. I of course don't remember it with 100% certainty, but I remember I used to be around 0.1-0.2ºC max off of temperature indicated by thermometer. (It rarely was over 38ºC, I'd say that's the point where sensitivity skills get quite challenged.)

Feeling the amount of fibre / sugar - eating apples

I like to eat an apple or two to freshen up during afternoons to do some more work at home. I like apples (with peel), because they always work for me, unlike bananas for example, most probably because apples contain lots of juice. I cut them into quarters and they sit next to my computer when I'm working, usually paying attention to other things than the plate, while apples quickly disappear.

I can pretty well tell when have I probably reached the healthy limit and start to feel too full. It is when I have eaten one and a half of two slightly larger apples.

If they are too big, I leave half of one for later. If they are too small, I look for one more. If I feel it was just about enough, things are perfect.

For number-lovers, I count 300g of apples as a portion. One and half of my-size apples (with the peel) contain 7.2g of dietary fiber and 31.2g of sugars.[3]

Therefore I am able to feel when I'm close to boundary of 7g of fiber or 30g of sugar. (It is fiber that's responsible for feeling of fullness when eating fruits and veggies.)

Estimating time when meditating

I meditate regularly with and app that I set to give a signal after every 5 minutes. My usual sessions last from 15 to 35 minutes.

When I was already meditating regularly for some time (probably few months) I once started to think “Have I really not turned on the sounds? ... No, it should be ok...”. After few moments: “Did my phone die?”

And right after that the bell would ring. I check the phone and the bell is set - as always - to 5 minutes interval.

After few more days like this I realized I have taught myself to estimate the 5 minutes just with practice. I cannot randomly estimate how much time has passed, but only that 5-minutes-moment should come now.

I am not sure at all if it's based on inhale/exhale subconscious counting (trying different breathing patterns or techniques quite distorts the skill), or if it's based on perceiving heart beats or if it is some other body signals. In any case, when doing my usual meditation, I can now pretty well tell when 5 minutes bell is about to ring with precision of very few seconds (in best cases) to roughly 30 sec (worse cases).

Exercise – exhaustion level

Quite obvious way to replace trackers with something else is to decide where exactly to run and check the distance ahead using an online map. By knowing rough distance between couple of points you should be quite set.

But I like to do another thing. Just run not to fit into desired number of steps or kilometers, but according to desired level of tiredness. When I used to run regularly, I had 5 degrees which seemed enough for my needs. 5 stood for 'Would hardly walk next day'. Putting my sneakers on I would decide to go for 2 or 3 (I somehow never kept my habit of running for too long so I my goal stayed low).

I do the same when going to swim to lake. I go to swim 3 times per one lake visit and each time I swim till the point when I start to have slight troubles sticking my head out of water to breath in. This way I know that next day I will be pleasantly worn out and feel my muscles. (One day I will look at the map to learn about the distance I swim so I have some basic idea of when is it that I start to drown.)

Estimation of level of tiredness (or being stressed-out)

There are evenings when I am so tired that I cannot see how tired I am and that the best would be to just close the computer, book or switch off the phone and just fall asleep.

But it has been couple of months since I noticed I somehow learned a new way to recognize that I crossed the border of being too tired – I simply notice that it has been long time since I have breathed in deeply. How long exactly I don't know, but my guess is in tens of minutes.

If this happens and I realize that I am not paying almost any attention to what I'm reading or doing, I know it's time to let things wait for some other time.

Only times I notice not breathing deeply for longer time is when I am tired, stressed at work, or ill.

What is the mechanism of this and why does it make any sense I do not know. I suppose it has to do with CO2 concentraton rising up in the blood on the expense of O2 which stresses out the whole body. Or maybe I just learned to keep a track of breathing 'in the back of my head'.

Estimate how long/well have I slept

At some point in my life I noticed those not-so-negligible differences in how easy or productive the day is depending on how many hours of sleep I got.

I need 8 to 8,5 hours a day so I can function as a person I identify myself to be and with ease, efficiency and joy. 7 hours makes a big difference compared to 8, I cannot concentrate and think clearly. I try to force it but it helps only a little. Unfortunately I cannot drink coffee as caffeine makes me only feel bad.

With six hours of sleep I am mentally roughly as sharp as with 7, but something in me is clear about that “It makes no sense to try and do the sharp-mind demanding things. Just do easier stuff today wherever possible.”

I became obsessed with checking when exactly I go to sleep, trying to guess in the morning how long did it take me to fall asleep and subtract the time when alarm clock rings to get the exact number. I learned to pair daily un-ease symptoms with different half-an-hour amounts of sleep that I estimated I got.

Can't remember the previous paragraph I just read? Not sure what login password did I just type in? I've slept 6 hours.

I got so many ideas reading this chapter and just wrote them all down with ease? 8,5 hours.

Feeling a bit foggy all day but not actually tired? Body coordination a bit funny? Probably between 7 and 7,5.

But over time I learned that this is something I actually do not want to know on my 30 minutes degree scale. It made everything less than 8 hours of sleep look miserable and I would postpone majority of what's important to have done.

I reduced my scale to two degrees, one standing for “I'm going to take a nap as soon as I get home” and another one “I am fine, let's do what I planned to do”. I still do care about whether I sleep well (and do almost anything I can to ensure this happens), but I really do not want to know the number any more or even think about it. Not knowing it made my life easier and ... more productive too.

Experiments and skills of others


"He was fascinated by their worship of nature and though them 'excellent geographers' because they could find their way even through the densest jungle. They were the best observers of nature he had ever encountered. They knew every plant and animal in the rainforest, and could distinguish trees by the taste of their bark alone - an experiment Humboldt tried and failed miserably. All fifteen of the trees he sampled tasted exactly the same to him."

This section cannot start without an example from ethnography. I found nice example in the book The Invention of Nature. The following excerpt describes Alexander Von Humboldt's learnings from indigenous people in Amazon rainforest.

Sensing Earth's magnetism

An article on Aeon presents studies that have been done to assess whether people are able to sense Earth's magnetism. In case you haven't heard of this, it mentions that “[...] flies, honeybees, ants and termites, snails, newts, various fish, frogs, sea turtles, lobsters, pigeons, mice, bats, mole rats, foxes, cattle and deer all have a magnetosense.”[1]

The article presents older and recent studies that suggest that humans should be able to feel the magnetic field of Earth too - when we need it and have good conditions for it.


That is when a short, usually click-like, sound is made and it's reflection from physical objects is perceived carefully by ears. Usually bats or whales are known to do this. But beware – there's a team of blind cyclists that can go mountain biking thanks to their learned skill of echolocation. And according to author Christian Jarrett “You don’t need to be blind to try it; even sighted people can learn to “see in the dark” using echo-location.”[4]

Have a look at TED talk How I use sonar to navigate the world or web of Visioneers or World Acces for the Blind for more information.

Intuition (a type of)

In one study participants played a card game. They were provided with $2000 and presented with two decks of cards, from either of which they could draw. Cards in the first deck offered both large financial gains and losses. Cards in the second deck offered smaller gains and losses.The goal of the game was to win as much money as possible.[5]

In the long run, players would win more money by drawing from second deck and it took most players between 50 and 80 draws for their left brain hemisphere to become aware of this. Their right brain hemisphere by contrast, fingured it out much faster.

The researchers were monitoring the sweat glands on plams of participants as way to measure nervousness. After mere 10 draws from the first deck, participants' palms began to sweat, indicating some part of their intelligence was aware of the risk far in advance of the conscious intelligence of the left brain.

Some participants actually never figured out that decks were rigged but their palms also sweated when taking cards from risky first deck.

It shows that right brain hemisphere can understand some situations faster and send not-so-articulated signals to our reasoning left hemisphere in a less direct form – we call them usually intuition or gut feeling. Sometimes we understand the hints, sometimes it is far too subliminal. I wonder whether this 'sense' can be trained.

Broken society

One thing that somehow stands out for me as a very visible element in the landscape of our sensitivity topic, at least in the west and westernized world, is how saturated so many things are. Most marketed and visible foods are full of sugars or salt; alcohol is present on so many occasions, foods loaded with sugars are part of our celebrations and social situations in all major cultures and I refrain to comment on most visible music, films and other media that feed other senses than taste or smell.

In my opinion it makes us used to only strong shades of colors or tastes and all other senses. For example in food, only tasty meals would be teriyaki chicken and if I don't feel like that today then there's pizza or cake. If I then tasted a meal from Scandinavia (sorry, people), I would find it bland, tasteless and uninteresting and would refuse to add such thing to as part of my reality. So as a result I eat only pizza, teriyaki or cake and my world remains small and my senses numb (dumb).

It might be partially understandable. If I work hard all day – which majority of us does – I want to have something different afterwards that gives me a good portion of pleasure or nice and sound break from my hard work. To afford these I need to work hard and long times (so the media tells us). And then I want to immediately and strongly satiate my needs. And so the circle perpetuates itself. (This is just one example of "supportive" mental mechanisms at work here.)

I don't think that things need to be like this and I think that some of the basis of our western culture and current globalized and globalizing system are utterly wrong. This affects us all the way down to the sharpness and delicacy of our senses and sensibilities. I suspect that work on sharpening one's senses (and mind with it) will ultimately lead to certain changes in our society.

Why do we work so hard and so many hours? Can't they cook a tasty meal without so much salt? Why so much sugar? Can't the cake be tasty with way less sugar? It totally can. I experience this on daily basis for many years now. (Yes, it meant some effort and exploration in the begining!)

Regarding all the listed experiments: it might all sound either weird or exciting and that there is some potential to it that would be interesting to investigate much further. There's an unfortunate fact about this at play that says that your conscious mind cannot access processes or information from more hidden deeper levels of our bodies or brain parts - neuroscience calls them 'automatic processes'.

So unless some mind-body hacker from Himalayas gives us a TED-talk on this, we have to wait for future to come and see what we have learned on the way there.

Until then I hope my friends will not soon need an app to tell them that they are thirsty while their smart watches penetrate their wrists with green light many times a second.

I would be happy to grow my list with similar sensitivity hacks of other people. If you thing you possess any relevant knowledge, please let me know at okram[a]protonmail.ch! I would love to make a sequel to this text.


1 – Human magnetism - https://aeon.co/essays/can-humans-navigate-by-sensing-the-earths-magnetic-field

2 – Paul Stamets in Joe Rogan's podcast - https://www.youtube.com/watch?v=mPqWstVnRjQ

3 – Apple nutrition facts - https://nutritiondata.self.com/facts/fruits-and-fruit-juices/1809/2

4 – Seeing in darkness - http://www.bbc.com/future/story/20141118-how-many-senses-do-you-have

5 – Rigged cards study – https://www.sciencedirect.com/topics/neuroscience/iowa-gambling-task - via book by Chris Niebauer called No self, no problem (2019).