❮   all STORIES

Understanding the Circular® Energy score: are you ready or not for the day?

Circular's primary goal is to ensure that our users are provided with the tools to live their lives to the fullest. That's why we built the Energy score. This is the ultimate score that tells you how much energy you have accumulated for the day. It is made up of many night and day contributors so that you can evaluate your vitality and know every morning if you can surpass yourself or if you may avoid over-training.

If you would like to know more about the metrics we talk about, you may refer to our articles relating to HRV, RHR, RR, Temperature variation, Circadian rhythm or Sleep cycles.

As with all Circular scores, a score equal or above 90 is Excellent, from 80 to 89 is Good and below 80 is Poor.


The energy levels score is a score that is composed of your last days:


  • Heart rate variability (HRV) 
  • Resting heart rate (RHR)
  • Breathing Rate (BR)
  • Oxygen level (SpO2)
  • Temperature variation
  • Activity volume
  • Body recovery
  • Sleep quality score & balance
  • Wake up score

All these parameters have different coefficients depending on their importance.

You might have already seen recommendations in your feed stating that all of your body signals are excellent and that you should be ready for any challenges. Or on the contrary, Kira might have told you that you should be careful and rest a certain day because your body signals are poor. 

Let’s discuss in depth what is taken into consideration in the Energy score and what are the implications for you. All of the following metrics are considered to determine whether or not you are ready for the day.


Heart rate variability (HRV)


HRV measures the specific changes in time (or variability) between successive heartbeats. It is used to see how well you recover after certain events, it is also a good measure of stress and anxiety and can unveil many things about your overall well being. It makes sense to take HRV into consideration as it is a general sign of a healthy condition. The higher it is the better: your body and immune system are then ready to tackle challenges during an upcoming day whereas the contrary would probably mean you need to rest.

Resting heart rate (RHR)


RHR is also a great measure for your overall health, correlated to your HRV. Although, this one focuses more on your fitness levels and is great at detecting minor heart conditions. A higher (compared to your baseline) RHR indicates poor overall wellness conditions. Coupling it to HRV and recovery gives us insights as to other factors that might affect your readiness such as medication you might be taking, irregular heart rate conditions, dehydration, an increase in temperature or even an increase in emotions.


Breathing rate (BR)

Breathing rate reported in respirations (breaths) per minute is an indicator of your cardiovascular load and is a good indicator of your wellbeing. You breathe harder and faster when you are ill or in need of energy.This metric varies much less than your RHR and HRV and is therefore much more stable. It becomes very useful when it increases a lot compared to your Reference. This metric acts as a threshold that can warn you when something is highly unusual. The difference between your daily value and your Reference shows to what degree you are in good condition or not. Normal values for a resting adult range from 12 to 18 breaths per minute. 

Oxygen level (SpO2)

Oxygen level (SpO2) is a measure of how much oxgen your red blood cells are carrying. The higher the better. Maintaining a precise balance of oxygen-saturated blood is vital to your health. It's a valuable metrics as it is closely related to respiratory conditions (shortness of breath, asthma, sleep apnea, and more...). A normal reading is typically between 94 and 100 percent. Monitoring oxygen level can help with prevention, altitude acclimatisation and recovery.


Activity volume


Activity volume is used to quantify whether you do enough physical activity according to the World Health Organization literature but also in comparison to your own amount of activity with your own baseline. It looks at your cardio points over a period of 1 week.


Body recovery


Recovery is a very important aspect to take into consideration when checking your overall condition (of course). Circular automatically checks your activity volume in the past 48 hours and also captures how long it takes for your heart rate to be at its lowest point during your sleep. The closer your lowest heart rate point is to the first part of your sleep, the better it is for a good sign of recovery.


Temperature variation


This contributor looks at the temperature variations occurring throughout your sleep compared to your baseline. It is an essential metric to evaluate how your natural defenses respond to your environment. 

When the variation is higher than +/- 0.8 degrees Celsius, that’s when you need to start paying attention. An advice would be measuring your body temperature with a thermometer. 

Any variance above or under your baseline can give a lot of crucial information. It can fluctuate with activity, your nutrition, your circadian rhythm, can indicate that your body fights against an illness, can reflect external environment changes such as a season change and can even reflect a woman’s menstrual cycle very clearly.


Sleep quality score & balance


It takes a number of contributions into consideration to determine your 2 last night's sleep; whether you slept long enough but also evaluate if it was of good quality sleep. 


Wake up score


Each time you wake up wearing the Circular ring either with or without the smart or non-smart alarm clock, you can find your Wake up score in the “Alarm clock” circle that evaluates in which sleep stage you woke up. The perfect moment for you to feel refreshed is to wake you up between your REM stage and the beginning of the light 1 sleep stage. At this perfect moment, you will receive a 100 score. Then the score is built depending on how far from the perfect moment is the sleep stage you were in when you woke up and also how far you were inside your stage.


What to deduce from the Energy score recommendations


If you get a recommendation saying that all your body signals are in the green: be assured that it means what it means. Every aspect of your body whether it is the immune system, stress levels or activity recuperation are excellent. It means that you can do intense activities, intense mental activities, having minimal risks of getting sick. You can push yourself throughout the day. If that’s what you usually go about, you’ll be able to do just that, better. Use good days like these to your advantage as they aren’t all that frequent (unfortunately).


If you get a recommendation saying that all your body signals are in the red: you guessed it, don’t push yourself. Kira takes sleep and previous activities into consideration, she knows how much rest or recovery you need. Our advice: If it’s cold be sure to cover yourself if you feel tired don’t hesitate to take a nap whenever you can and don’t hesitate to go to bed a little bit earlier. 



The Energy score is part of the Circular® Global score, click here to learn about it.  


We remind you that the Circular™ ring is not a medical device and should not be used to diagnose or monitor a pathology.

Amaury Kosman

CEO of Circular, Amaury is all about technology and human capabilities improvement. He is a dedicated marathon runner and loves optimizing his training.

You might also like