Heart rate variability (HRV) is a powerful way to see how your body’s self-regulating systems are working right now — whether you’re handling stress well, recovering, and ready to perform.
Every heartbeat happens with a slightly different interval, and those tiny differences tell a big story about how your body’s systems are doing. When your body is balanced, the intervals between heartbeats change flexibly. When you’re tired, stressed, sick, or short on sleep, that flexibility drops.
HRV is used in sports, medicine, psychology, and even space research as an objective measure of physical condition. Scientists have published over 22,000 studies on PubMed linking HRV to stress, fatigue, focus, and overall health. In simple terms, it’s a science-backed way to see how your body reacts to everyday life — to sleep, work, coffee, emotions, and workouts.
Keep in mind: HRV measurement isn’t an ECG or a medical diagnosis — but our technology has been validated to match ECG-level accuracy, as confirmed by a study published in an Elsevier journal.
At Welltory, we use HRV to create your Heartbeat Report — giving you clear, data-driven feedback from your body, without guessing or subjective impressions.
Your Heartbeat Report shows:
the current state of your nervous system
whether your body is ready for activity or needs recovery
In short, Welltory’s Heartbeat Report is your personal tool for self-regulation.
It helps you understand yourself better, build effective habits, and recognize when your body is quietly saying: “Take a break.”
Where to find your Heartbeat Report
You can find your report in your Feed or in the Journal:
On iOS: tap the Journal icon in the bottom navigation bar or go to Menu → Journal.
On Android: tap the Journal icon in the bottom navigation bar.
Your Journal brings everything together in one place — your Heartbeat Report, workouts, daily activity, sleep, and notes about your blood pressure, mood, and weight. It’s your daily story, told through data.
What reports do you get
After each measurement, you’ll see two reports in your Feed:
The histogram message — this one includes the standard HRV metrics such as SDNN, pNN50, RMSSD, AMo50, CV, and others. These values are based on general population norms and don’t yet reflect your individual data, habits, or activity level.
The liquid message — built on top of your HRV data, this is where we show your personalized Welltory metrics: Stress, Energy, Focus, and Health. The liquid space fills up to visualize your current state, so you can instantly see how balanced your body is.
In your Journal, we’ve combined both — the histogram and the liquid message — into a single Heartbeat Report that gives you a full picture of your body’s condition in one place.
Inside your Heartbeat Report
The liquid and measurement data block
On the first screen, you’ll see the core of your report — the liquid space, which shows how active your body is right now.
When the liquid looks calm and steady, it means you’re in balance — your nervous system is stable, and your body is handling stress with ease.
If the liquid starts bubbling or swirling, your regulatory systems are working hard: you might be tense, tired, or in active recovery mode. The color of the liquid reflects your overall state — from green when you’re energized and healthy to red when your body is overloaded.
You can gauge how you’re doing in just a second — no numbers, no charts.
It’s a visual language that helps you see when it’s time to go for it and when it’s better to slow down and recharge.
Below, you’ll find the measurement data block — showing your heart rate, total beats recorded, and accuracy level. It helps you quickly understand whether your reading was reliable or if you should redo the measurement for more accurate results.
Detailed Report
HRV statistics give you a clear view of how your body changes over time.
The trends show when you’re recovering, when you’re overloaded, and which habits truly help you stay in balance. Instead of isolated measurements, you see your whole story — how your energy, focus, and resilience shift day by day. It helps you understand what keeps you in good shape — and what quietly drains your resources.
Health shows how resilient your body is to stress, strain, and illness. It reflects your body’s functional reserves — its ability to stay in balance when conditions change.
A high Health score means your body is coping well, even if you feel tired or under the weather. A low score means your system is struggling and needs more rest, sleep, and recovery.
The chart helps you see your real condition, not just how you feel. Sometimes you might feel fine, but your body is already running on empty — and Health will show it before symptoms appear.
Our algorithm calculates this parameter purely from HRV data, without analyzing any symptoms. That’s why it shouldn’t be compared to things like body temperature or subjective well-being — it’s an objective physiological signal, not an emotion.
Note: All information is provided for general wellness purposes only and is not a medical diagnosis. If you’re feeling unwell, please consult a healthcare professional.
Focus reflects your readiness for mental work — thinking, analyzing, and making decisions.
A high Focus score means it’s the perfect time for deep work, learning, and creative problem-solving. A moderate score is great for routine tasks. If your Focus is low, don’t push yourself — your brain simply won’t switch on fully, and productivity will drop.
The chart helps you match your tasks to your current state — so your day flows naturally instead of turning into a fight against fatigue.
Focus is closely tied to Stress and Energy: when those are in balance, your mind works sharply and efficiently. But when you’re tired, sleep-deprived, or overstimulated, your concentration naturally goes down — and that’s okay.
Energy reflects your body’s ability to recover, handle stress, and stay balanced.
A high Energy level means your body is coping well and still has reserves to draw from. A low level means your system is working hard just to maintain internal stability — a clear signal to slow down and recharge.
The chart helps you see whether you have enough strength for everything on your plate and adjust your daily rhythm before you burn out.
The Energy trend shows the direction your body is moving — whether it’s spending, rebuilding, or staying balanced. It helps you anticipate dips and surges in energy, so you can plan your work, workouts, and rest more wisely.
Sometimes your Energy level may be high even if you feel tired — that means your body has already switched into recovery mode, and your strength is on its way back.
In a few hours, you’ll likely feel more refreshed — your system is already one step ahead.
If you’re sick but your Energy score stays high, that’s a good sign: your body is maintaining balance and coping well with the stress.
Stress reflects your level of physiological tension — how actively your body’s regulatory systems are working right now. It’s not about emotions or mood. It shows how mobilized or relaxed your body is at this moment — how hard it’s working to handle the load.
When Stress is high, your body is in overdrive and struggles to recover. In this state, the sympathetic nervous system is highly active, releasing more cortisol and adrenaline. It’s your survival mode: you’re alert, focused, and productive — but at the cost of burning through your resources faster. This often happens after an intense workout, a tough day, emotional strain, or illness.
If your Stress level spikes after activity, that’s normal — your body is simply restoring balance. But if it stays high for several days, that’s a sign to slow down: you’re close to overload, and rest will do more good than any push for productivity. Consistently high Stress without a clear reason usually means your body isn’t getting enough recovery — not enough sleep, nutrition, or downtime.
When Stress is very low, your body is deeply relaxed. That’s great in the evening or on a day off — but if low Stress comes with low Energy, it may mean your system is drained and has “powered down” to conserve strength.
A low morning Stress score is a good sign: you’ve recovered and are ready for the day. Later in the day, though, unusually low Stress may point to exhaustion — your body just doesn’t have enough fuel left to stay engaged.
The optimal Stress range is your “working state” — when your body is alert but balanced. This level means your system has adapted and manages energy efficiently. It’s the best time for focused work, conversations, training, and decision-making.
The chart helps you spot when to ease up or, conversely, when to push yourself a bit more. By keeping an eye on your Stress levels, you can reduce the risk of chronic fatigue and burnout.
Sometimes, physical Stress doesn’t match emotional stress. For example, after exercise or an exciting event, your physiological Stress may be high even if you feel great. That just means your body is still running on adrenaline and needs time to return to balance.
Remember: Stress isn’t the enemy — it’s part of how your body adapts. What matters is not staying in overdrive for too long.
Experimental data
Nervous system balance shows how active your nervous system is overall and how this activity is distributed between its two main branches:
Sympathetic — responsible for stress response, focus, and physical or mental activity.
Parasympathetic — responsible for recovery, relaxation, and rest.
The values are shown as percentages and reflect which system is more active right now.
Balance naturally shifts throughout the day: in the morning, the sympathetic system helps you get going; in the evening, the parasympathetic system helps you unwind.
The chart shows what mode your body is currently in — ready for action or in need of slowing down. But what matters most isn’t just the ratio between the two systems — it’s the total level of activity.
If the overall activity is low, your nervous system is sluggish, meaning your body is tired and needs rest. If it’s high, your body is alert, and your nervous system is responding flexibly to whatever’s happening around you.
For people who practice yoga, breathing exercises, or meditation, the balance between sympathetic and parasympathetic activity is a great real-time indicator of how effective those practices are.
The HRV Score is a numerical measure of your heart rate variability, calculated from lnRMSSD — a key marker of parasympathetic nervous system activity.
A higher HRV Score means your body is more resilient to stress, recovers faster, and adapts more easily to physical or emotional challenges. A score near 100% reflects an ideal state — your body reacts flexibly to whatever comes your way, and your performance, especially during workouts, is at its best.
Your HRV Score is an objective measure of your internal reserves. It helps you track progress after rest, meditation, training, or sleep adjustments.
Coherence shows how synchronously your body’s internal systems — the brain, heart, and breathing — are working together.
High Coherence means those systems are in harmony: you react less to stressors, think more clearly, and feel emotionally steady.
You can increase your Coherence with breathing techniques (like coherent or deep breathing). Positive emotions and calm thoughts also help — this effect is well-documented in physiological research.
Note: To calculate Coherence, your measurement must include at least 80 heartbeats. If this metric isn’t shown, your reading was too short for an accurate analysis.
Raw data
Right after each measurement, you’ll receive a message in your Feed with a set of core heart rate variability metrics — SDNN, pNN50, RMSSD, AMo50, CV, and others. These are scientifically validated parameters used across HRV research, sports science, and medicine.
Physiologists, coaches, and doctors around the world rely on these exact metrics to assess physical condition and recovery.
However, it’s important to understand that these are not personalized values.
They’re based on general population norms and don’t yet reflect your unique lifestyle or habits.
You can explore these parameters in more detail in your Journal, under the Heartbeat Report section. In your Feed, they appear in a separate histogram message.
What the metrics show:
How many parameters are currently within the normal range — a quick way to see how balanced your body is right now.
SDNN value — one of the key HRV indicators, showing the overall stability of your nervous system.
Histogram — a chart that visualizes how the intervals between your heartbeats are distributed during the measurement.
The histogram is one of the classic tools in HRV analysis. When the sympathetic and parasympathetic systems are in balance, their shape resembles an isosceles triangle — a sign of harmony and stability. When the triangle becomes sharper and steeper, it indicates stress or strain — your regulatory systems are working harder than usual.
The color of the chart helps you understand your state instantly:
Green — all good, you’re in balance.
Yellow — within acceptable limits, but worth watching the trend.
Red — outside the normal range, your body is under strain.
The position of the histogram also shifts with your heart rate: a higher heart rate moves it left, while a lower heart rate shifts it right.
Inside the message, you’ll also find:
Rhythmogram — a chart showing how the intervals between beats changed during the measurement. It also displays the total number of intervals, which reflects the length and reliability of your reading.
Time-domain parameters (RMSSD, SDNN, pNN50, etc.) — describing how your heart rhythm fluctuates from beat to beat.
Spectral analysis (Total Power, VLF, LF, HF) — showing how heart activity is distributed across different frequency bands.
You’ll only see Spectral Analysis if your measurement includes at least 300 RR intervals — this amount of data is required for accurate frequency-domain calculations. To enable it, just tap Turn on right in the report.
Your Heartbeat Report reveals how your nervous system is functioning, whether your body has enough resources, and how resilient you are to stress and load. It helps you make simple, informed choices — whether to rest, act, or adjust your day based on your body’s current state.