Customer Reviews for Garmin - Index Sleep Monitor Size: S/M - Black - (2025)
Customer Rating
5
Must have for Garmin users
on August 9, 2025
Posted by: Bill92264
For anyone tracking their data 24/7, this is a gamechanger. Way more comfortable than a watch (I literally forget I’m wearing it), and seems to be more accurate as a sleep tracker. Worth every cent.
So the device itself is pretty good. Easy to use, comfortable, doesn't annoy me like wearing a watch does at night.
What does bug me is that it doesn't always properly show sleep in Garmin Connect. Some days it'll say "Wear a device for 3 days to get performance metrics" even though I have been wearing the watch or Index Sleep at all times. Other times it'll show "recent sleep" but the last sleep doesn't show. It just inconsistent and devalues it.
I've been wearing it every night for over a week, and aside from an additional device on my arm im not sure it's doing anything differently than my watch has been doing for a few years.
I definitely like this option over wearing my watch at night. However, I find that the band slips off sometimes during the night. Additionally, I’m not impressed with the battery life. For only being used at night to monitor sleep, the next versions battery life has to be extended. As I said, the idea is there and Garmin makes great products.
I like this for the ease and comfort of the device application and metrics obtained. The battery life is excellent, but Garmin is particularly known for the longevity of its batteries. This is just another addition to the long line of Garmin products I own, and I am happy to add it to my collection of wearable health devices.
The sleep monitor is much more comfortable than wearing a watch to bed. The strap is the most comfortable strap that I have ever worn on my bicep. It was so comfortable, I bought extras for other devices that I am testing.
I do have some concerns about the data compared to wearing my FR265 at night after the first 10 days wearing the device. The HRV readings overnight using the Index have averaged in the mid 60s, but my FR265 was consistently in the mid 70s (my Apple Watch records in the 70s & 80s), so Garmin connect has been showing that my HRV status is low because of this. My resting heart rate has also slightly increased 3-5bpm using the Index. My 3/5 rating of the device is based on these concerns about accuracy compared to the FR265.
The sleep times wearing the device have been within a few minutes of my Apple Watch sleep times. I don't pay too much attention to the sleep stages though. I am not convinced that they are too accurate on any wearable device.
I have tried to wear the device all day to see if it could be a legitimate Whoop competitor to wear at all times when I am not wearing my Forerunner 265, but it falls short because it does not record steps (which makes no sense because the device surely has an accelerometer) or intensity minutes. It does continue to record your heart rate whenever you are wearing it, but it will miss some of the higher spikes of heart rate if you wear it during the day while doing intense exercise. It does work if these things don't bother you, but keep in mind that the device is not designed to wear 24x7.
Men definitely should go for X/XL size. Band is tighter than expected. It's wide and I feel it more than the watch. Maybe I got used to wearing my FR965 while sleeping