Garmin CIRQA - First Tests!

Name: Garmin CIRQA - First Tests!
Uploaded: 2026-07-27T18:13:30.000Z
Duration: 19 min 41 s
Channel: The Quantified Scientist

The Quantified ScientistJuly 27, 202619m

Topics26

Garmin Circa Introduction and Key Questions0:00 Testing Plan and Methodology0:31 Pre-Arrival Research and Garmin Responses1:31 Hardware Specifications2:00 Exercise Type Challenges for Optical Sensors2:30 Physical Button and Activity Profiles3:00 Heart Rate Broadcasting Capabilities4:00 Automatic Activity Detection4:30 Wearing Location and Algorithm Adjustments5:30 Sleep Stage Algorithm and Smart Alarm6:32 Garmin Connect Data Priority System7:31 Recommended Usage Pattern8:30 Overlapping Activity Rules9:00 Battery Life Details9:32 Initial Excitement and Setup Process10:30 Initial Testing Setup11:01 Unboxing and Initial Setup12:01 Setup Process and Primary Wearable Selection13:31 Initial Testing Results Overview14:31 Running Session Results14:31 Indoor Cycling Issues and Performance15:01 Indoor Cycling Results Assessment16:02 Running Session Challenges16:30 Biceps Band Delay and Future Testing17:30 Weightlifting Results18:30 Overall Initial Assessment19:00

In a Nutshell

Garmin's new Circa is a screenless optical heart rate band using the Elevate V4 sensor, which can be worn on wrist or biceps and integrates with existing Garmin watches through a primary wearable priority system. Initial tests show the Circa performs well for indoor cycling but has mixed results for running and weightlifting, with some heart rate artifacts and delayed responses compared to a Polar H10 chest strap reference. The device supports heart rate broadcasting, automatic activity detection, and uses the same sleep stage algorithms as Garmin watches, with the option to set it as primary wearable for daily metrics while using a GPS watch for workouts.

AI-Generated Notes

These notes were generated by AI and may contain inaccuracies.

Garmin is entering the screenfree wearable market with their new Circa device. Several important questions cannot be answered by simply looking at the device. These include what happens when wearing the Circa alongside another Garmin watch, which device gets priority when recording data with both devices, whether the Circa uses the same sleep stage tracking as Garmin watches, and whether wearing it on the upper arm actually changes the measurements.

The sample should arrive within the next hour or two. The testing plan includes answering all questions about device priority and data handling, then setting up the Circa and immediately putting it through its first real tests. The tester is Rob, a post-doctoral scientist specializing in biological data analysis, with the focus being on data and data analysis.

Testing will include an outdoor run, an indoor cycling session, and weightlifting. Heart rate measurements will be compared against a reference device in ECG chest strap, showing actual results including where it performs well and where it might struggle. This will only be an initial impression of its performance. For real testing, multiple rounds of each type of exercise are planned, along with outdoor cycling. Sleep, heart rate, heart rate variability, and sleep stages will also be examined over the coming week or two for a more complete set of data for the first proper review.

Before the Circa arrives, details that could be just as important as raw measurement accuracy need to be addressed. An extensive list of questions was asked to Garmin about the Circa, including which optical sensor it uses, how its automatic activity detection works, whether its algorithms are adjusted when worn on the wrist versus the biceps, and how the Garmin Connect app handles data when using both the Circa and a Garmin watch.

Garmin sent detailed answers, several of which are really interesting. These questions will be addressed first, then the Circa will be set up and testing will begin once it arrives.

According to Garmin, the Circa comes with the same Elevate V4 sensor found in some of the cheaper Forerunner models. This is the fourth generation of the optical heart rate sensor together with a skin temperature sensor. This is not Garmin's newest optical heart rate generation. However, the generation of a sensor does not automatically tell how accurate the final measurements will be. The cheaper Forerunner models were already really good.

The fit of the device, the placement on the arm, the algorithms, and the type of movement can have a substantial effect. Given that the Circa is quite light, it might actually do relatively well, which is exactly what will be tested during several very different exercises.

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Garmin CIRQA - First Tests!

Garmin Circa Introduction and Key Questions00:00

Testing Plan and Methodology00:31

Pre-Arrival Research and Garmin Responses01:31

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