Xiaomi smart bracelets have long ceased to be simple pedometers — modern models like the Mi Band 8 Pro, Smart Band 7 Pro or Watch 2 Pro are equipped with dozens of sensors that monitor the state of your body around the clock. But what really hides behind the numbers on the screen? Why is the indicator SpO₂ 92% can be an alarm, and heart rate variability (HRV) of 20 ms - a reason to visit a cardiologist? In this article, we will analyze all the metrics that captures the smart bracelet Xiaomi, including hidden parameters, which the manufacturer does not mention in the official instructions.
Many users mistakenly assume that the bracelet simply counts steps and shows time, but in fact, the device analyzes sleep in 4 phases, detects sleep apnea, assesses stress levels from the pulse, and even predicts the menstrual cycle in women, while the accuracy of readings depends not only on the model of the bracelet, but also on the correctness of wearing it. For example, if you wear the Mi Band too loose, the pulse sensor will record false jumps, and the data on calories will be inflated by 30-40%.
1. Main health indicators: pulse, SpO₂ and blood pressure
The three key parameters that any Xiaomi smart bracelet tracks are heart rate (HR), oxygen saturation of the blood (SpO₂) And blood pressure, in the new models, let's look at how they're measured and what abnormalities mean.
The pulse rate (HRF) is recorded using an optical sensor PPG (Photoplethysmography. The bracelet shines green LEDs on your skin and analyzes how blood absorbs light. Normal values:
- 🩺 At rest: 60-80 beats / min (athletes can have 40-50 beats / min).
- 🏃 Walking: 90–110 beats/min.
- ⚠️ Anxiety: above 100 at rest (tachycardia) or below 50 without physical fitness (bradycardia).
SpO₂ (oxygen saturation is measured by an infrared sensor, 95 to 100 percent normal:
- 🟢 96-100%: optimal level.
- 🟡 92–95%: mild hypoxia (maybe you sleep on your back or in a stuffy room).
- 🔴 Below 92%: Critical fall - check your breathing, especially if you have shortness of breath.
⚠️ Attention: Sensors SpO₂ Xiaomi bracelets have an error ±If your Mi Band 7 is 93%, the real value could be 91-95.
Blood pressure in Xiaomi bracelets (for example, in the Watch) 2 Pro is measured indirectly by pulse wave and AI algorithms, accuracy is lower than that of a blood pressure monitor, but trends are tracked well. 140/90 mm Hg. art. and above - this is an occasion to measure the pressure in the classical way.
2.Sleep Analysis: Phase, Apnea and Improvement Tips
One of the key advantages of Xiaomi bracelets is sleep monitoring by phase: deep sleep, light sleep, REM-phase (rapid eye movement) and wakefulness, but how to interpret these data?
Normal phase distribution in an adult:
- 🌙 Deep sleep: 15-25% of total time (recovery).
- 🌓 Light sleep: 50-60% (transitional states).
- 👁️ REM-Phase: 20–25% (information processing, dreams).
If the bracelet fixes:
- ⚠️ Less than 10% deep sleep: chronic fatigue, possible breathing problems (apnea).
- ⚠️ Frequent awakenings (more than 5 per night): stress, noise or uncomfortable posture.
- 🚨 Apnea (Breathing Stops): If the bracelet shows more than 5 episodes per hour, see a sleepr.
| Parameter | Norma. | Deviation | Possible cause |
|---|---|---|---|
| Deep sleep. | 15–25% | <10% | Apnea, alcohol before bedtime |
| REM-phase | 20–25% | >30% | Stress, depression |
| Frequency of awakenings | 1-2 times | >5 times | Pain, noise, restless legs syndrome |
How do you improve your sleep according to your bracelet? If the Mi Band shows poor sleep quality,
Lie down and get up at the same time (scattering no more than 1 hour)|Eliminate caffeine 6 hours before bedtime|Ventilate the room (optimal temperature 18-20)°C)|Wearing a bracelet on an unworking hand (usually the left hand)|Turn off notifications 1 hour before bedtime-->
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If the bracelet fixes apnea, try sleeping on your side - this reduces the number of respiratory arrests by 50%.
Stress Level and Energy Balance: What Do the Numbers Mean?
Xiaomi models since the Mi Band 6 measure stress levels by heart rate variability (HRV), which measures how quickly your heart adapts to exercise, and the higher your HRV, the better.
Deciphering stress levels in the Mi Fitness app:
- 😊 1–39: relaxed state.
- 😐 40–59: moderate stress (normal during the day).
- 😨 60–100: High stress – a pause is needed.
The energy balance (available in Mi Band 7 Pro and later) shows how much energy you're wasting and recovering. If the balance is negative for several days in a row, it's a signal of overwork. For example, if you've slept 6 hours and the bracelet shows, "Energy deficit: −20% means the body has not had enough time to recover.
⚠️ Attention: The stress assessment algorithms in Xiaomi bracelets don’t take into account individual characteristics. For example, in people with arrhythmia, HRV may be artificially understated, and the bracelet will consistently show “high stress” even in calmness.
4. Physical activity: steps, calories and exercise
The basic function of any fitness bracelet is to count steps and calories, but how does Xiaomi do that?
The stepmer works on the basis of an accelerometer and a gyroscope, and the accuracy depends on:
- 👟 Hand positions: if the bracelet on the wrist of the working hand (right-handed), it will count the extra "steps" when moving with a mouse or keyboard.
- 🚶 Type of walking: with a slow walk, the error is up to 10%, when running - up to 3-5%.
- 📱 Synchronization with the phone: if it is enabled GPS, Accuracy improved by satellite adjustments.
Calories are calculated using a formula that takes into account:
- 🔥 Weight and height (indicated in profile).
- 🏃 Type of activity (walking, running, cycling).
- ❤️ Pulse during loading.
For example, if you weigh 70 kg and walk 10,000 steps, the bracelet will show about 300-400 calories, but the actual flow rate can vary by 20-30% due to individual metabolism.
Training modes in Xiaomi bracelets (for example, in the Watch) S1 Pro) supports up to 150 sports, from yoga to rowing, and algorithms adjust calorie counting and analyze the mode of choice:
- 🏊 Swimming: records the number of strokes and style.
- 🚴 Bicycle: speed, distance (if connected) GPS).
- 🏋️ Strength training: activity time and pulse in load zones.
Why does the bracelet count when I am in the car?
5.Women's health: tracking cycle and ovulation
Menstrual tracking feature appeared in Xiaomi bracelets since Mi Band 5.
- 📅 Fix the beginning and end of the period.
- 🔮 Predict the next menstruation (accuracy) ±2 days).
- 🥚 Determine the days of ovulation (by changing the basal temperature, if you wear a bracelet at night).
- 📊 Analyze symptoms (pain, mood swings).
How does it work?
- You manually enter the start date of the cycle in the Mi Fitness app.
- The bracelet tracks changes in heart rate and body temperature (at night).
- The algorithm predicts ovulation 5 days before it occurs (peak fertility).
⚠️ Attention: Xiaomi bracelets are not a contraceptive! ovulation prognosis is about 80% accurate, which is not enough to protect. Use LH or folliculometry tests to plan pregnancy.
Useful chips:
- 🔔 Set up notifications about the approach of monthly (for 1-3 days).
- 📈 Compare cycles in dynamics – the bracelet will show if there were failures (for example, delay of 5 hours).+ days).
- 🌡️ In models with a temperature sensor (for example, the Watch) S1 Active) basal temperature can be monitored to confirm ovulation.
6 Additional Features: Weather, Notifications and Smart Home Management
Beyond health, Xiaomi smart bracelets are a universal assistant, and consider the less obvious but useful features:
Weather and forecast:
- 🌦️ The bracelet syncs with the Mi Fitness app and shows temperature, humidity, pressure.
- ☔ If it is expected to rain, a notification will appear (configured in the weather menu).
Smart home (works with the Mi Home ecosystem):
- 💡 Control the Yeelight or Philips Hue lights directly from the bracelet.
- 🔌 Turn on/off the Xiaomi Smart Plug sockets.
- 🚪 Open the Xiaomi Smart Lock (if the bracelet is tied to your account).
Notifications and prompt action:
- 📱 Support for notifications from messengers (WhatsApp, Telegram), calls and SMS.
- 🎵 Managing music (pause, next track) on the phone.
- 🔍 Phone Search feature – the bracelet vibrates if the phone is far away.
Payment and transportation (in models with NFC, For example, watch. S1 Pro):
- 💳 Linking Bank cards for contactless payment.
- 🚇 Emulation of transport cards (for example, “Troika” in Moscow).
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Xiaomi bracelets with NFC (For example, Mi Band 7 Pro support payment through Mi Pay, but only in partner banks (Sberbank, Tinkoff, VTB).
7 Hidden possibilities: what does the bracelet know, but does not advertise?
The manufacturer doesn't always talk about all the features, but here are the hidden chips that Xiaomi has in its bracelets:
1.Do Not Disturb Mode on Schedule
You can set up automatic notifications, for example, from 23:00 to 7:00.
Mi Fitness → Profile → Bracelet settings → Do not disturb2. Quickly unlock the phone
If the bracelet is connected to a Xiaomi smartphone, you can unlock the phone without entering a password (you need to turn on the phone security settings).
3. The hidden mode "Theatre"
Turns off the backlight and the vibration, but leaves the pulse tracking.
On the bracelet: Settings → Screen → Theater Mode4. Customization of dials
Mi Fitness has a hidden collection of dials that don't show up in the main menu.
- Open the Mi Fitness app.
- Go to the section "Profile" → Bracelet settings → Dials».
- Pull the screen down and there will be more options.
5. Export of data for the doctor
In the application Mi Fitness you can create a report on sleep, pulse and activity for the month in the format PDF. It's convenient for consulting a cardiologist or a somnologist:
Mi Fitness → Health → Health Report → Export