Why people think it’s fake

Welltory is an app that lets anybody with a smartphone measure their stress & energy levels in minutes, completely free. The app also gives users extensive information about their heart, nervous system, sleep quality, and more.

Watch this video for a quick explanation of how it works:

We often get incredulous feedback during presentations or in comment sections:
“I don’t believe this is possible,”
Or “More pseudo-science,”
Or “Look at these people claiming to be mind-readers.”

Welltory may seem to good to be true, so we decided to break things down for you. Here’s how the app works.

How can you track heart beats with a phone camera?

Everyone knows that you can check your pulse by putting two fingers over your wrist or neck. You can also do this with a phone camera.

The heart pumps blood throughout the body. As the heart beats, blood flows in and out of your blood vessels, including the capillaries in the tips of your fingers.

Changes in blood flow can be measured with the help of a technique called photoplethysmography.

What is photoplethysmography (PPG)?

PPG is a method that has been around for over 50 years. In 1972, NIHON KOHDEN engineer Takuo Aoyagi discovered that variations in arterial blood volumes can be estimated based on light absorption fluctuations caused by arterial pulsations. In 1975, NIHON KOHDEN released a device that used this non-invasive method to track heart rate. The world’s first pulse oximeter didn’t do well on the market, but it provided a solid foundation for further developments. 

By 1990, over 30 companies were manufacturing pulse oximeters, and sales reached 65,000 units annually. The devices illuminate capillaries in the user’s finger, then track changes in color that happen due to changes in blood volumes. Welltory uses the phone’s flash to illuminate the capillaries, and the camera to track the changes.


The same method is used by companies like MIO alpha-MIO Global and Philips use to conduct research. Researchers and healthcare professionals actively use PPG as well. You can learn more about it here.
In other words, Welltory did not come up with this technique. It’s a trusted method that is widely used in healthcare and medical research. We have simply made it available through the phone’s camera. We illuminate the finger and take a video that tracks how the color of your blood vessels change, then use it to count your heart beats.

This is why we ask you to put your finger over the camera and flash at the same time. The flash illuminates the capillaries in your finger while the camera records changes in blood flow.

Can you measure anything other than heart rate?

Your heart rate is just the average number of times your heart beats per minute.

We also track the intervals between heart beats. Your heart does not beat evenly, which means the time intervals between your heart beats vary. This variation is what our analysis focuses on, and it gives us a lot more information about your body.

Let’s do a quick thought exercise borrowed from Nassim Taleb.

Do you think a grandmother would be ok if placed in a room with an average temperature of 70 degrees fahrenheit for one hour?
 You would probably say yes.
But say the temperature jumps from below freezing to 120 degrees every five minutes. You would definitely change your mind.

This is the difference between a pulse, which gives you an average, and the information we get by measuring the time intervals between heart beats.

Heart rate variability (HRV) is a technique that helps us use these time intervals to understand what’s happening with your heart and nervous system. HRV is widely used by researchers and healthcare professionals, racking up over 20,000 publication on PubMed.

Here is the idea: your heart does not beat evenly because it’s always adapting to external factors. This ability to adapt shows how stressed your body is and how much energy you have left. It reflects the state of your heart and nervous system, tracking stress and recovery processes in the body. The higher your heart rate variability, the healthier you are.

According to Dr. Roman Bayevsky, who invented the method, “heart rate variability is like a window into the body’s key organs and regulatory systems.”


Dr. Bayevsky initially used HRV to track astronaut health, and the method was successfully used to monitor the first manned flight into space. HRV continues to be used in healthcare, research, professional sports and, of course, space science.

For example, the Venezuelan basketball team used heart rate variability to train for the 2016 Olympic Games in Rio. The hockey team Red Wings uses HRV analysis to track athlete recovery on a regular basis. The same applies to many NHL teams and other athletes.

Formulas for analyzing heart rate variability have been standardized by the Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. HRV analysis results generate a list of parameters that can be used to assess health: 

Healthcare professionals and researchers can use these numbers to figure out what’s happening with your heart, nervous system, etc. You can also access these parameters in “Measurement details” after every measurement.

What are our Stress & Energy numbers based on?

Heart rate variability is a great method that can give you a ton of information. As you can see above, there are a bunch of numbers that aren’t easy to interpret.

Welltory simplified all of these parameters into two user-friendly indicators: stress & energy. They’re much easier understand. Your stress level shows how well you’re coping with external stressors, and energy is how much life force you have left.

The numbers reflect the balance between stress and recovery that you need to manage in order to stay productive. 

All we did was make a well-researched and widely used technique available to anybody with a smartphone. We use formulas developed by healthcare professionals and show you simple estimates that help you understand what’s happening with your body.

Moreover, these simplified parameters will help you understand which lifestyle factors affect you most – what helps cut down on stress or boost your energy levels.

For example, this chart shows that the user burns less calories when they’re stressed:

Is anyone else doing this?

Our developer team made measurements with a camera simple, but there are other companies using similar techniques and algorithms.

Most of them do so with the help of gadgets, relying on heart rate monitors instead of smartphone cameras. Welltory is compatible with a lot of these heart rate monitors, so you can plug them into our app and use them instead of the camera.

Keep in mind that your device needs to measure heart rate variability in order to be compatible with Welltory. While most gadgets track your heart rate, not all of them measure heart rate variability.

Here is a short list:
Firstbeat — used by several Olympic teams
Polar —  the most popular manufacturer of chest straps for runners
Whoop — used by NBA players
AliveCor — used by the MayoClinic

Yes, these gadgets cost a lot of money and these are all great companies, but Welltory does the same thing for free. All you need is your phone camera.


See how simple it is?

New technological breakthroughs mean that we can collect more information about ourselves than ever before. We used to be able to measure temperature, blood pressure, and heart rate. Now we can also track heart rate variability to get more insights about ourselves. And most importantly, we don’t have to visit a doctor’s office to do so. All you need is your phone!

Download Welltory: #iOS #Android

Other articles:
1) More about photoplethysmography method

2) Heart Rate Variability assessmentt is a new feature in Welltory ap – https://welltory.com/detailed-breakdown-en/



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