Your Garmin Forerunner 955 tracks everything from your morning run to your heart rate zones. But what happens when it suddenly stops recording your sleep? You wake up, check the app, and there’s nothing. No sleep score, no stages, no data at all.
This issue frustrates runners and athletes who rely on sleep metrics to optimize recovery. Missing sleep data means you can’t track patterns or make informed decisions about training intensity.
This guide walks you through why your watch might stop tracking sleep and shows you exactly how to fix it. You’ll learn the common triggers behind this problem and get step-by-step solutions that work.
What’s Happening With Your Sleep Tracking
Sleep tracking on your Forerunner 955 works by monitoring your movement and heart rate throughout the night. The watch uses these signals to determine when you’re asleep, what stage of sleep you’re in, and when you wake up. The technology is pretty reliable, but it needs specific conditions to work properly.
When sleep tracking fails, you’re left with gaps in your recovery data. Sleep metrics influence your Body Battery score, training readiness, and overall health snapshot. Without this information, your watch can’t give you accurate recovery recommendations. You might push too hard on a day when you actually needed rest.
The watch needs to detect consistent periods of inactivity combined with specific heart rate patterns. If something disrupts these signals, tracking stops. Sometimes the issue is simple, like wearing the watch too loosely. Other times, software glitches or incorrect settings prevent the watch from recording anything at all.
Here’s what makes this problem tricky:
- The watch might look like it’s working fine during the day but still fail at night
- Sleep data doesn’t sync immediately, so you won’t know there’s a problem until morning
- Multiple factors can cause the same symptom, making diagnosis harder
- Battery saver modes can disable tracking without clear warnings
Garmin Forerunner 955 Not Recording Sleep: Common Causes
Several factors can prevent your Forerunner 955 from recording sleep data. Some are obvious, while others hide in your watch settings or happen because of software bugs. Let’s break down what’s actually stopping your watch from doing its job.
1. Wrist Detection Issues
Your watch needs consistent contact with your wrist to track sleep. If the band is too loose, the optical heart rate sensor can’t get clean readings. The watch thinks you’ve taken it off and stops recording data.
This happens more often than you’d think. You might wear your watch comfortably during the day but loosen it before bed. Even small gaps between the sensor and your skin cause problems. Hairy wrists, tattoos near the sensor, or moving your arm during sleep can all break contact.
The sensor needs firm, steady contact without being uncomfortably tight. If you can easily slide the watch up and down your wrist while wearing it, that’s too loose for reliable sleep tracking.
2. Sleep Mode Not Enabled
The Forerunner 955 has a dedicated sleep mode that optimizes tracking during rest. Without this mode active, the watch might not recognize when you’re actually sleeping. It could mistake lying down for sitting on the couch or interpret tossing and turning as being awake.
Sleep mode tells your watch to prioritize rest detection over activity tracking. It adjusts sensitivity levels and changes how the watch interprets movement patterns. Accidentally disabling this feature means your watch goes back to treating nighttime like any other part of the day.
3. Battery Saver Mode Active
Battery saver mode extends your watch’s life by disabling non-essential features. Sleep tracking falls into that category. When battery drops below a certain threshold, the watch might automatically enable this mode and shut off sleep monitoring without telling you.
You might charge your watch during the day and think you’re fine. But if the battery dips low enough overnight, tracking stops mid-sleep. You wake up to find partial data or nothing at all.
Low battery also reduces sensor accuracy even before battery saver kicks in. The optical heart rate monitor needs power to work properly, and running on fumes affects its performance.
4. Software Glitches or Outdated Firmware
Software bugs can break sleep tracking entirely. A corrupted file, failed update, or system conflict might prevent the watch from recording data even when everything else works fine. Garmin regularly releases firmware updates that fix known issues, but running old software means you’re stuck with unfixed bugs.
These glitches often appear after major system updates or when multiple apps run simultaneously. Your watch might freeze during the night, restart on its own, or simply stop recording without any visible error message.
5. Incorrect Sleep Schedule Settings
Your Forerunner 955 uses your sleep schedule to know when to actively monitor for rest. If these times are set incorrectly, the watch might not track your actual sleep hours. Working night shifts, traveling across time zones, or having irregular sleep patterns can confuse the watch.
The watch looks for sleep during the window you’ve defined. Going to bed earlier or later than your schedule means the watch isn’t expecting you to sleep yet. It continues normal activity tracking instead of switching to sleep mode, and you end up with no recorded data.
Garmin Forerunner 955 Not Recording Sleep: DIY Fixes
Getting your sleep tracking back on track doesn’t require technical expertise. Most fixes take just a few minutes and solve the problem immediately. Start with the simplest solution and work your way through until sleep data starts appearing again.
1. Adjust Watch Fit and Positioning
Proper watch placement makes all the difference. The sensor on the back needs solid contact with your wrist throughout the night. Wear the watch about one finger-width above your wrist bone. Tighten the band just enough that it doesn’t slide around but doesn’t cut off circulation.
Clean both the sensor and your wrist before bed. Dirt, lotion, or sweat can create a barrier that blocks accurate readings. Make sure no clothing bunches up under the watch band during sleep.
Test the fit by checking if you can see the green light from the heart rate sensor glowing against your skin. If you see the light clearly shining through gaps, tighten the band another notch.
2. Enable Sleep Mode and Check Sleep Settings
Your watch needs sleep mode turned on to track properly. Here’s how to verify and enable it:
- Press the Up button to open the menu
- Scroll to Settings and select it
- Find User Settings and tap it
- Select Sleep Mode
- Toggle it to On
While you’re in there, check your sleep schedule. Tap on Sleep Schedule and make sure the times match when you actually go to bed and wake up. Add buffer time on both ends if your schedule varies. The watch will start monitoring an hour before your scheduled bedtime.
3. Charge Your Watch Fully Before Bed
Battery issues kill sleep tracking faster than anything else. Make charging part of your evening routine. Plug in your watch while you eat dinner, shower, or wind down. Aim for at least 40% battery before bed, though a full charge is better.
Check if battery saver mode is already on. Press and hold the Light button, then look for the battery saver icon. If it’s active, turn it off before sleeping. You can manually disable it through the Controls menu.
4. Update Your Watch Firmware
Garmin fixes sleep tracking bugs through software updates. Connect your watch to the Garmin Connect app on your phone. Open the app, tap the menu icon, and select Garmin Devices. Choose your Forerunner 955 from the list.
Look for Software Update and tap it. If an update is available, download and install it. Keep your watch close to your phone during the entire process. Updates can take 10 to 15 minutes depending on file size.
Your watch will restart after updating. Once it powers back on, check that all your settings are still configured correctly. Sometimes updates reset preferences to default values.
5. Restart Your Watch
A simple restart clears temporary glitches that prevent sleep tracking. Hold down the Light button for about 10 seconds until the watch turns off. Wait a few seconds, then press the Light button again to turn it back on.
After restarting, go through your sleep settings one more time to confirm everything is enabled. Test the setup by lying down for 10 minutes during the day and checking if the watch recognizes rest periods.
6. Contact Garmin Support
If none of these fixes work, you might have a hardware problem. Faulty sensors or damaged components need professional attention. Reach out to Garmin support through their website or call their customer service line.
Have your watch’s serial number ready before contacting them. You’ll find it in Settings under About. They might ask you to try a factory reset or send diagnostic data. If your watch is still under warranty, they’ll repair or replace it if there’s a defect.
Wrapping Up
Sleep tracking problems on your Forerunner 955 usually come down to fit issues, disabled settings, or low battery. These fixes get your watch recording again so you can monitor recovery and optimize training. Most people solve the issue by adjusting watch tightness or enabling sleep mode.
Start with the simplest solutions first. Check your watch fit, verify your settings, and make sure you’re charging properly. If problems continue after trying everything, hardware failure might be the culprit. Support can help you figure out next steps and get you back to tracking those rest hours.