Do you ever wonder why your energy fluctuates during the day or why on some days you feel like you could take over the world while on other days you feel like your batteries are totally empty?
What if you could understand why?
Would it be valuable?
If so, keep reading.
I’m a big data freak and gadget nerd.
I proudly admit I’ve tried probably all fitness, sleep, mood, and productivity tracking apps on the Apple store and many outside of it. Some were great, others just gimmick.
Just as businesses track marketing performance, sales, revenue, etc., so they can grow and improve, if you want to improve and optimise your health, energy level, and overall performance, you need to track your body performance and know what works and what doesn’t.
The power of science.
Storytime: As a teenager, I had a motorbike, JAWA 350cc.
When you looked at it, you knew it could tell a few stories, but if you pulled the right strings it could still run like a “pinched swine” (Czech saying). It had carburettors and all, and to fix something on it, all you needed was pretty much just a hammer and a screwdriver.
Every time I was going to start the engine (by jumping on the starting lever) it involved a great deal of strength, hope and luck.
Here she is, in all her shiny beauty.

My older brother, on the other hand, had a racing bike Honda FireBlade 900RR. Quite a different story there. All computer-controlled, and if you wanted to tweak something, you plugged in your laptop, load up the diagnostics to see how the engine is performing and adjust the setting if you need to.

I always thought: Wouldn’t it be cool if you could get the same diagnostics for my own body?
Well, you can.
A couple of years ago, I discovered Welltory.
(I can’t believe I’m only sharing all this with you now).
“Welltory is an app that analyses heart rate variability β a health marker backed by over 25,000 studies.
First designed to track astronaut performance in the 1960s, HRV analysis quickly gained a reputation as a reliable health assessment method applicable in fields like healthcare, high-performance sports, and military training.
Today, HRV is used by researchers, healthcare professionals, and pro athletes to track stress, recovery, systemic inflammation, and overall nervous system balance.
HRV or heart rate variability is NOT the same as heart rate, which is simply the number of beats per minute.
Heart Rate Variability is the difference in time between heartbeats (scientifically named R-R intervals ), measured in milliseconds.”

What Causes Heart Rate Variability?
“Your heartbeat varies because your body is always adapting to changes.
It responds to anything that happens to you: a jog, a cup of coffee, or even an upsetting post on your newsfeed.
The heart generates impulses and beats on its own. Different regulatory systems modify this beat in your body. Their job is to respond to external stressors by speeding up or slowing down the heart rate to help keep your body’s internal environment stable.
The signals sent by these regulatory systems are always playing tug-of-war with your heartbeats, which is what makes your heart rate variable.
It is generally accepted that your heart rate variability measurement depends on the balance between your regulatory systems (the scientific term is the Autonomic Nervous System (ANS), which encompasses parasympathetic (PNS) and sympathetic (SNS) activity.)
The ANS has two branches: the sympathetic branch (often called “fight or flight”) that motivates us to react and perform, and the parasympathetic branch (“rest and digest”) that allows the body to recover after stressful events (physical or mental stress).
Welltory does more than interpret HRV. We’ve built algorithms that use it to make sense of data from people’s apps and gadgets β a machine that tests hypotheses against your data, and sends you insights about your wellbeing, productivity, mental health, and more. These insights are Predictive, Personalised, Preventive, and Participatory β the 4P’s that are key to making healthy living simple and accessible.”
Now, let me share with you how I use Welltory and the awesome insights it generates to better understand how different activities affect my energy level, health, productivity, and stress level.
With these insights, I can then plan my workload around what my body can handle on any given day or hour.
Welltory – insights
Let me show you how Welltory insights look.
NERD ALERT!

When you click on the insight, you get even more detailed analysis which I find fascinating.
Let me show you two quite different readings.
The first one is really positive as you can see all in green.
Well, it was a Bank Holiday Monday.


The second reading is from the day before, after a 20km run.
You can see, it took quite a lot out of me.


I use my Apple Watch to take measurements of my heart, but you can also use the phone camera by placing your finger on it for a couple of minutes. It works the same way as the little clip you get on your finger in a hospital. It shines light through your finger and reads your heart rate by measuring the variation of the colour of your skin/flesh under it which changes slightly throughout each heartbeat as blood goes through your finger. Fascinating, isn’t it?
The way I use Welltory is by taking several measurements through the day.
I’m not too strict about it but there are a few typical times when I do it:
- Morning: This gives me a good idea about the quality of my sleep.
- Mid Morning: Usually after my workout, so I can see how much energy it took out of me.
- Early afternoon: Just to see how I’m doing. If my energy is low sometimes I take a power nap or take it a little easier overall.
- After work/ evening: I’ve observed it helps me determine whether I need an earlier bed or not.
Welltory also gives you a whole day overview with your activity level and the measurements overview so you can see how your energy fluctuate during the day.
As you can see at the bottom of the image, different colours of the line mean different activity level. From sleep, to mediation, to just being active as well as exercise.
But wait, there is more. Much more.
Welltory Integrations
Welltory can integrate with many different wearables and apps.
From that you get mind-blowing insights into how different app usage affects your energy, mood, performance, the list can go on and on.
I simply cannot praise Welltory enough.
If you’re serious (or curious) about understanding how your body works, what helps it and what hurts it, when you can push your limits and when you need to take it easy, then Welltory is like having your own research lab in your hand.
Check it out, give it a try, and thank me later.

Thanks for the review! It’s really useful.
Pleasure. Glad it’s useful.
Good stuff Tomas! I use the Oura ring which tracks similar features. Huge fan of all this science!
Hi Nick, yeah I’ve heard Oura ring is great as well. Haven’t got it myself yet but thinking about it.
Going to have it in my phone right away! Thanks for the recπ
Definitely do Shivang. Let me know how you like it.
App measurement continues to indicate stress although at 72 years old, I work out 12 exercise classes a week [kickbox, ripped, yoga, core and more]. I do not feel that the indication is correct, same results after 3 days of holiday – no workouts. Repeated indication with suggesting that I am more prone to get a “cold” because of it. The app seems to keep me interested and keeping track and documentation of BP and app related measurement, but seems to be intent on upselling from the free portion. I am now stuck on “updating” my feed to see my measurement results, which I am not able to do after using the app religiously for about a month, doing so multiple times a day. Upon trying to communicate with the app about the glitch, I am not able to find a source for an answer. I am not able to see much in terms of multiple reviews, good or bad. I am not able to find much about heart rate variability, outside of the app
Hi Mark, thanks for the comment. I’m not sure if you have a specific question. Sounds like you’re in great shape! Have you seen the web version of the insights and correlations?