Sleep Data - Deep Sleep Accuracy?

Former Member over 8 years ago

Hi All,

Does anyone know how the Deep Sleep data is measured?

I've had my fenix 5 for a week now, wake/sleep & awake times seem pretty close to what I expect based on how I felt in the night but the first five nights deep sleep has ranged from 9 to 12 MINUTES only.

Last night I apparently got 5 hours of deep sleep, which is an anomaly compared to every other night so far has been reported as around 10 minutes.

I've done nothing different each night, strap at the same tightness, snug and worn all day & night.

Cheers.

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0 --Fred-- over 8 years ago

Hi All,

Does anyone know how the Deep Sleep data is measured?

I've had my fenix 5 for a week now, wake/sleep & awake times seem pretty close to what I expect based on how I felt in the night but the first five nights deep sleep has ranged from 9 to 12 MINUTES only.

Last night I apparently got 5 hours of deep sleep, which is an anomaly compared to every other night so far has been reported as around 10 minutes.

I've done nothing different each night, strap at the same tightness, snug and worn all day & night.

Cheers.

I wouldn't worry about it, it's more of a gimmick than an instrument. I think anyway it's better to take the watch off at night rather than have Bluetooth radiation all night.

0 mcalista over 8 years ago

Hi All,

Does anyone know how the Deep Sleep data is measured?

I've had my fenix 5 for a week now, wake/sleep & awake times seem pretty close to what I expect based on how I felt in the night but the first five nights deep sleep has ranged from 9 to 12 MINUTES only.

Last night I apparently got 5 hours of deep sleep, which is an anomaly compared to every other night so far has been reported as around 10 minutes.

I've done nothing different each night, strap at the same tightness, snug and worn all day & night.

Cheers.

Just a thought, but with a week's worth of data, your Fenix 5 is probably now starting to get dialed in with YOUR training load, resting HR, VO2Max, etc rather than just using population averages. This may affect how it interprets your heart rate overnight.

0 Former Member over 8 years ago

Hadn't put too much weight into it to be honest, just curious.

I like to leave it on overnight assuming that helps give a better resting HR average?

0 mcalista over 8 years ago

I wouldn't worry about it, it's more of a gimmick than an instrument. I think anyway it's better to take the watch off at night rather than have Bluetooth radiation all night.

Just on the issue of radiation, we are talking about Bluetooth LOW ENERGY. These things run for weeks on just a coin battery, and if you want evidence of how low power they are, just think about how quickly they lose the signal once you move more than a very short distance away. BLE runs on a fraction of the emitted power of wifi, which is in turn a fraction of the power of your cell phone. And despite thousands of studies, there is no credible evidence that cell phones cause health problems, so the likelihood of something that works on less than 1% of the EMF of a cell phone causing problems is to all intents and purposes zero.

And if despite the facts, you are still concerned about it, just turn the BT on your watch off overnight.

But on the gimmick issue - I do wonder about some of the features coming up in the latest generation of watches, and whether the data they produce is in fact actionable in any meaningful way. I know when I have had a #$%^ night's sleep without my watch telling me.

0 Former Member over 8 years ago

I beg to differ about knowing if you've slept well. It can be very helpful. As a person with issues sleeping, the tracking function tells me something other than my skewed perception.
When I am awake at funny hours and drift in and out of sleep, I am usually very happy to see that I slept more than I thought when I look at my stats.
It calms me down and helps me get out on my bike without wondering if I will be compromised by lack of sleep.
Or I know I shouldn't risk going outside, dodging cars, rather put the bike on a trainer and practice better sleep hygiene for the next night.

0 AliLumsden over 3 years ago in reply to mcalista

I have had both a vivoactive followed by a fenix 5. The Viv used to record around 2 hours of deep sleep yet the fenix consistently shows less than 30 mins. I wish Garmin would fix this, it’s clearly an issue with Fenix 5. I also agree sleep data is super useful when looking at your wider health picture. I use Inside Tracker and it is constantly telling me I have a bad health marker with limited deep sleep.