In recent weeks I have run a few times with a Suunto Race On my wrist next to a pectoral heart rate. Was necessary to try Zonense, the novelty presented a few months ago by Suunto. I wanted to understand her well and try her for myself.
The truth is that it is an inventazo.
What exactly Zonese is?
Zonese is Suunto’s new technology to measure our intensity during exercise. The usual thing is to count pulsations per minute, but Zonese analyzes the Heard rate variability (VFC) To determine, in real time, how our body is responding to effort.
- The VFC is the variation in time between each heartbeat. Not all beats have exactly the same temporal separation, and these small variations contain valuable information on how our autonomic nervous system is working.
- High variability usually indicates a good state of recovery, while a low variability indicates fatigue or stress.
The interesting thing is that This VFC changes during the exercise very specificly according to the intensity with which we work. And it is just this relationship that Zonese takes advantage of an algorithm called DDFA (Analysis of dynamic fluctuations without a trend) to determine in which metabolic area we are training.
And that serves to optimize anyone’s training. Either an expert athlete who wants to increase his performance, or either a person who simply wants to go for a walk to lose weight and wants to do it in the optimal way.
Three areas that change everything
The training areas, or heart rate, are five, although according to whom you ask (including sports watches manufacturers) can give you six or seven. Zonense simplifies training only three colors:


Image: Xataka.
- Green (aerobic zone). When your body is working mainly with oxygen and fats as fuel. It is the ideal zone for long training, recovery or fat burning. Your body could be kept here for hours. Do you want to go for a walk to lose weight? This is your area. Do not stay below or above.
- Yellow (anaerobic). Your body begins to use more glycogen and begins to produce lactate, although it can still process it. It is the “threshold” area, where performance improvements are important, but you can’t stay here for too long.
- Red (Vo2max). You are above your anaerobic threshold, your body produces lactate faster than you can eliminate. It is where the greatest adaptations of power and speed are achieved, but you can only maintain this effort during short time spaces.
He Vo2max It is the maximum amount of oxygen that your body can process during intense exercise, is what measures our aerobic capacity.
Why Zonese needs a heart rate
A key aspect of Zonese is that it requires a heart rate. The optical wrist sensor that incorporates the watches is not enough, and there is a scientific reason for it.
Optical sensors They measure the pulses by calculating changes in blood flow by lightbut They cannot accurately detect the exact intervals between beats nor the small variations necessary for the VFC analysis during the movement.
Chest bands, however, directly detect the electrical impulses of the heart (such as an ECG), providing the necessary precision for this advanced analysis. In my tests I have used the Suunto Smart Sensor.
It would be much better not to have to use it and limit us to the clock, but if these bands maintain their popularity it is for something: they are more reliable, precise and complete.
My experience
The first time I went to run with Zonense, I planned a 10 km training at a soft rhythm. Normally, based on my heart rate, I would run at about 5:30 min/km to keep my “aerobic zone”.
However, after the initial 10 minutes that Zonese needs to calibrate (establishing your metabolic baseline of the day), the clock showed me that it was in yellow (anaerobic), despite the fact that my heart rate was just 145 ppm, which would traditionally consider as my area 2-3.
It turns out that last night (several, in fact) he had slept badly and also came from three consecutive days of intense training. My body was telling me, through Zonesethat although the pulsations were not extremely high, it was metabolically working harder than traditional numbers suggested.
I reduced the rhythm at 5:47 min/km and, indeed, I returned to the green zone. The training was much more pleasant and, surprisingly, the next day I felt quite recovered, something that would probably have happened if I had maintained my “normal” rhythm.
On another occasion, after a week of rest, Zonese allowed me to maintain a faster rate (5:15 min/km) remaining in the green zone. My body was cooler and could work at greater intensity without entering anaerobic areas.


Image: Xataka.
This type of Personalized and dynamic adjustment is what makes Zonense so valuable. They are not just numbers on a screen, it is real information on how your body is responding to exercise at that precise moment.
Another striking example: the shoes. With which I used for filming I marked VO2Max from 4:47 min/km, while when I went to flying I had to go down to 4:19 min/km to enter that area.
Not only for elite athletes
One of the biggest surprises has been to verify the usefulness of Zonese for people who are barely starting to play sports or simply go for a walk. It is common for a beginner to feel overwhelmed at the explanations of cardiac areas and to remove calculations from its theoretical maximum frequency.
For this type of users, Zonese says something much simpler: “Stay in green”. With that simple instruction, the user will walk at a pace that maximizes fat burning without entering areas of greater intensity where the body begins to use glycogen. And it will avoid going too slow.
And best of all: being real -time and calibrated information after ten minutes of activity, that user may be in the green or yellow zone depending on the day even if he is walking at the same pace, depending on whether he has rested little or is stressed.
Zonense helps to understand that exercise is not something rigid, but we must adapt it to how we meet every day.
Science after simplicity
Zonese is based on Monicardi’s worka company derived from the University of Tampere, which developed the DDFA index. This algorithm has been the subject of several scientific studies that show its correlation with lactate tests and ventilatory thresholds carried out in the laboratory.


Image: Suunto.
Unlike other systems, Zonense does not require introducing personal data such as age, weight or height to function. The algorithm detects patterns in cardiac variability and establishes thresholds based exclusively on these real physiological data.
Monicardi researchers have published scientific articles on the methodpresenting evidence of how the pattern of cardiac variability changes predictably at the points where metabolic transitions occur during exercise.
The limitations
Not everything is perfect. Zonese has some limitations that we must know to make the most of technology and not carry us disappointments:
- You need warming time. To work properly, Zonese needs about 10 minutes of data to establish your baseline of the day. This means that you should start your workouts gradually.
- It is not ideal for very short intervals. In sessions with intervals of less than 3-4 minutes, Zonese may not have enough time to detect changes in intensity. It works better with sustained efforts.
- Requires a heart rate. As I mentioned, the optical watch sensor is not enough. This adds an additional component that you should carry.
- Only available in real time in the most recent models. Although the subsequent analysis is available for all its watches when a cardiac band is used, real -time visualization is only possible in Suunto 9 Peak Pro models, vertical, Race, Race S and Ocean.
ZONESENSE vs. The competition
I have spent years running with an Apple Watch on the wrist until Say the jump to Garmin almost two months ago. I have also been attentive to what other important manufacturers do here, such as choirs. What suggests with Zonese is really different.
Most brands use training areas based on fixed percentages of your maximum or threshold heart rate. This means that if your aerobic threshold is, for example, in 160 ppm one day that a race, the clock will assume that it is always there, regardless of your state of fatigue, rest or stress.


In the post-carrier metrics of the mobile app can be seen in detail, comparing it with other metrics such as our heart rate or our speed. Image: Xataka.
Some more advanced systems, such as Garmin FirstbeatThey try to consider factors such as resting cardiac variability to estimate your recovery status, but continue to use fixed areas during exercise.
Zonese takes a step further by analyzing VFC during the exercise to determine your metabolic thresholds at that time. They are not estimates based on historical data or formulas, but direct measurements How your cardiorespiratory system is responding to effort.
It is like comparing a thermometer that measures the outside temperature right now, with one that gives you an average based on the historical data of recent days.
Differential
After almost a month of intensive use, I can say that Zonese is one of the most striking advances in recent sports technology. It approaches significantly to what you would get in a laboratory, but in a non -invasive and continuous way.
I have not done lactation analysis in laboratory, but some users have documented an impressive correlation between blood lactate measurements and the areas that Zonese shows.
Its great advantage over a laboratory test is The constant update: While a test gives you a fixed photo of a specific day, Zonese provides you with information adapted to your daily changes. It is the closest thing to having a sports physiologist by your side, without punctures or masks.
Zonese has allowed me to adjust the intensity to my real state. For a serious athlete, it offers data that until now were only available in professional environments. For beginners, simplify the understanding of training areas.
Does it justify to change your function for this function? It depends on how much values the precision in the measurement of intensity. If you are looking for a dynamic adjustment of your areas, Zonese offers something right now in the market. It has democratized an above -exclusive technology of elite laboratories and athletes, making it accessible to all with a simplicity that benefits both the occasional and experienced ultramarratonian corridor.
Even who only wants to walk a little to lose fat.
Outstanding image | Xataka
These devices (Suunto Race, Suunto Smart Sensor) have been ceded for test by Suunto. You can consult How do we do the reviews in Xataka and ours Business relations policy.