Xiaomi Mi Band 4: how to use a fitness bracelet and how to use it

The Xiaomi Mi Band 4 fitness bracelet has become one of the most popular activity monitoring gadgets thanks to its combination of affordable price and wide-ranging functionality. This compact device can track steps, pulse, sleep quality, and manage notifications from a smartphone. But how exactly does it work? What technologies are behind it, and how to properly configure the bracelet for maximum efficiency?

In this article, we will go into detail about how the Mi Band 4 works, its key features and hidden features, how to sync your device with the Mi Fit app, interpret health data and avoid typical operating errors, and compare the Mi Band 4 with newer models to see if it’s worth upgrading.

Technical specifications and "stuffing" Mi Band 4

Underneath the compact body of the Xiaomi Mi Band 4, a whole suite of sensors and modules that make it work.The core of the bracelet is the Dialog DA14680 processor, an energy-efficient chip optimized for wearables, which consumes minimal power, allowing the bracelet to last up to 20 days on a single charge (when used as a standard).

Among the key components:

• 🔹 Optical pulse sensor (PPG) — Measures the heart rate with accuracy ±5% compared to medical devices.
• 🔹 3-axis accelerometer – tracks body movements, determines steps, distance and activity (walking, running, swimming).
• 🔹 Bluetooth 5.0 BLE — Provides stable communication with the smartphone at a distance of up to 10 meters.
• 🔹 AMOLED-resolution-screen 120×240 pixels – supports touch control and display of color notifications.

The bracelet is equipped with 5 ATM moisture protection, which allows you to use it in the rain or in the pool (up to 50 meters deep).However, it is worth remembering that the Mi Band 4 is not designed for diving or hot baths - high temperatures and steam can damage electronic components.

⚠️ Warning: If you have water left under the bracelet after bathing, dry it for 1-2 hours before charging.

How Mi Band 4 tracks physical activity

One of the big questions users have is, how does the bracelet count steps and determine the type of activity? It's all about the combination of data from the accelerometer and machine learning algorithms. The sensor captures the acceleration of the hand in three planes (X, Y, Z) and analyzes the nature of the movements.

• 🚶 Walking: smooth rhythmic oscillations with an amplitude of 0.5-1.5 m / s².
• 🏃 Running: sharper acceleration peaks (2–4 m/s2) with high frequency.
• 🏊 Swimming: cyclic movements with low amplitude but long duration.

Xiaomi's algorithms are trained on thousands of hours of recordings from real users, so the bracelet is quite accurate in distinguishing, for example, cycling from walking. But errors are still possible - for example, if you actively gesture with your hands while talking, the bracelet can count extra steps.

To improve accuracy, it is recommended:

Wear a bracelet on a non-working hand (for right-handed - left, for left-handed - right)

Periodically calibrate the pedometer in the Mi Fit application

Turn on GPS on your smartphone to record running/bicycle routes

Update the bracelet firmware to the latest version-->

Fun fact: The Mi Band 4 can automatically recognize 6 activities, including walking, running, cycling, gym, swimming and an elliptical trainer, but for accurate calorie counting, it is better to manually select the workout mode in the wristband menu.

Heart Rate Monitoring: How It Works

The pulse sensor in the Mi Band 4 uses photoplethysmography (PPG) technology, which is based on measuring changes in blood volume in the wrist vessels. Green LEDs illuminate the skin, and the photodiode captures reflected light. When the heart beats, blood flow increases, and the intensity of the reflected signal changes, which is converted into a pulse rate.

It is important to understand that the accuracy of measurements depends on several factors:

• 🩹 Density of fit: the bracelet should sit tightly, but not squeeze the hand (optimally - 2-3 cm above the carpal bone).
• 🌡️ Skin temperature: Cold fingers or poor circulation can distort data.
• 💦 Sweat or dirt: Moisture between sensor and skin blocks signal.
• 🚫 Tattoos: Dark skin patterns absorb LED light, which interferes with measurements.

By default, the bracelet measures your heart rate every 30 minutes in standby mode and continuously during exercise. To change your frequency, go to Device Profile → Settings → Monitor your heart rate in the Mi Fit app.

⚠️ Warning: If the bracelet is constantly showing a pulse above 100 beats per minute at rest, check the density of the attachment.

Sleep Tracking: How the Bracelet Analyzes Phase

Xiaomi Mi Band 4 uses a combination of data from an accelerometer and a pulse sensor to analyze sleep.

1. Waking up is a period of waking up (for example, if you get up at night).
2. Light sleep is a transitional phase where the body relaxes but the brain is still active.
3. Deep sleep is the most important phase for the recovery of the body.
4. REM-sleep (rapid eye movement phase) – associated with information processing and dreams.

For accurate analysis, the bracelet should be worn just before bed and remain on your arm until you wake up. If you take it off at night, the data will be incomplete. Mi Fit visualizes your sleep schedule and gives recommendations for improving it, for example, advises you to go to bed earlier if the deep sleep phase is too short.

Tip: to make the bracelet more accurate at the time of falling asleep, do not move your hand in bed before going to bed (for example, do not flip the tape on your phone).

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If the bracelet misidentifies sleep phases, try putting it on the other hand or turning on Sensitive Sleep mode in the Mi Fit settings.

Synchronize with Mi Fit and set up notifications

Without the Mi Fit app (or its Zepp Life alternative), the Mi Band 4 bracelet works like a simple pedometer, and to unlock the full potential of the device, it needs to be connected to a smartphone:

1. Download Mi Fit from Google Play or App Store.
2. Sign up or sign in to your Xiaomi account.
3. Turn on Bluetooth on your phone and add a new device in the app.
4. Follow the instructions on the screen for pairing.

After you connect, you can:

• 📱 Set up call notifications, SMS and messages from messengers (WhatsApp, Telegram, etc.).
• 🌍 See detailed statistics of activity, sleep and heart rate in the charts.
• 🔄 Update the bracelet firmware to access new features.
• 🎨 Change dials (more than 50 options available in the Mi Fit store).

To enable notifications, go to Device Profile → Notifications and select the apps you want to see on your wristband. Note: Mi Band 4 only displays notification text (without emojis and pictures) and does not support responses to messages.

⚠️ Note: If notifications don't come, check: Is Bluetooth on your phone? Is Mi Fit allowed to send notifications in settings Android/iOS. Has the bracelet been added to the list of “low energy devices” (on Android).

Mi Band 5/6: Should I Upgrade?

The Xiaomi Mi Band 4 remains a current device even years after its release, but newer models offer a number of improvements.

If you want basic functions (stepmeter, pulse, sleep, notifications), the Mi Band 4 is still a great choice, but if you want advanced health metrics (blood oxygen, stress, breathing) or more accurate tracking of workouts, consider upgrading to the Mi Band 6 or later.

Also, the Mi Band 4 doesn’t support NFC (unlike the Mi Band 4 NFC version), so it can’t be used for contactless payments.If this feature is important, look for the Mi Band 5 NFC or Mi Band 6 NFC models.

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Mi Band 4 is perfect for basic activity and sleep monitoring, but if you need advanced health features (SpO₂, stress NFC, Consider upgrading to Mi Band 6.

Typical problems and their solutions

Despite being reliable, Mi Band 4 users sometimes face challenges, and here are the most common ones and ways to fix them:

1. The bracelet is not synchronized with the smartphone

• 🔄 Reset the bracelet (press the touch button for 10 seconds).
• 📱 Reinstall the Mi Fit app.
• 🔌 Turn off and turn on Bluetooth on your phone again.
• 📡 Make sure the bracelet is not connected to another device (e.g., a tablet).

2.The battery is discharged quickly

• ⚡ Turn off constant pulse monitoring (leave only "During exercise»).
• 🔕 Reduce the brightness of the screen in the bracelet settings.
• 🚫 Disable notifications from unnecessary applications.
• 🔄 Update the firmware – in new versions optimized energy consumption.

3. incorrectly counts steps or calories

• 👟 Wear the bracelet on the opposite hand (for right-handers - left).
• 📏 Enter the exact height and weight in the Mi Fit profile.
• 🎯 Calibrate the pedometer: walk 100 steps and compare with the bracelet data.

If the problem persists, try resetting the bracelet to factory settings. To do this, go to Settings → Reset in the device menu.

FAQ: Answers to Frequent Questions