Shervin Shares's Fitbit Air Review

The Fitbit Air provides generally good heart rate data for running, comparable to an Apple Watch and a chest strap, though it can have initial inaccuracies. For rowing, it is good, but not great.

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The Fitbit Air delivers very accurate heart rate tracking during swimming, performing better than the Apple Watch Ultra 3 and closely matching FORM Swim Goggles.

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The Fitbit Air lacks a built-in GPS and relies on a connected phone for location tracking.

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While relying on a phone's GPS means less accuracy than a dedicated sports watch, it is 'good enough' for casual activities like walks, runs, or bike rides, but not ideal for serious training.

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Deep sleep duration, as reported by the Fitbit Air and other consumer wearables, shows significant variability when compared to a medical-grade EEG headband. While the Fitbit Air can be 'pretty close' and sometimes outperform others for its price, all wearables struggle with consistent sleep staging.

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The Fitbit Air is generally accurate for total sleep duration, aligning closely with a Somni EEG headband and other devices, with less variability than deep sleep metrics.

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The Fitbit Air provides excellent step counting accuracy, performing very similarly to the Apple Watch, making it a strong and affordable option for tracking daily steps.

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Readiness and recovery scores generated by the Fitbit Air, like other consumer devices, are highly inconsistent and vary significantly between different wearables, making them unreliable for critical daily decisions.

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Heart Rate Accuracy - First Run

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In a comparison with the Apple Watch Ultra 3 and a Garmin chest heart rate strap (HRM-600), the Fitbit Air recorded an average heart rate of 156 BPM, matching the Apple Watch and being very close to the chest strap's 158 BPM. The graphs appeared 'pretty on par' with a bias of 1.8 BPM or 0.1.

Heart Rate Accuracy - Second Run Issues

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During a second run, the Fitbit Air had initial issues with heart rate data, showing it 'jumping around' or not being 'on tight enough,' but it stabilized later. The divergence from the HRM-600 was +1.2 BPM, which was deemed 'excellent' for the stabilized period.

Heart Rate Accuracy - Swimming

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While swimming, the Fitbit Air's heart rate data was very close to the FORM Swim Goggles, which the reviewer considers more accurate. The Apple Watch struggled due to its larger size and water movement.

Heart Rate Accuracy - Rowing

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During rowing, the Fitbit Air's heart rate data appeared 'jumping around a lot' due to arm movement. The average heart rate was close to the Apple Watch, but with a 2.6 BPM difference, rated 'good, not great'.

Lack of Built-in GPS

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The Fitbit Air does not have a built-in GPS and relies on the user's phone for assisted GPS tracking during workouts.

GPS Accuracy for Casual Use

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The phone's GPS, which the Fitbit Air uses, is 'good enough' for casual runners or those who just want some data tracked. It's not recommended for specific training where high accuracy is crucial.

Deep Sleep Duration Variability

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Comparing deep sleep across devices (Somni EEG, Eight Sleep, Fitbit Air, Oura Ring, WHOOP, Apple Watch) for one night showed extreme variability, ranging from 28 minutes to 3 hours and 17 minutes. The Somni EEG tracked 1.5 hours.

Total Sleep Duration Comparison

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Most devices, including the Fitbit Air, seemed 'pretty close' to the Somni EEG headband for total sleep duration. The Oura tended to be under, and the WHOOP overcalculated, especially when watching movies.

Overall Deep Sleep vs. EEG

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Over 11 days, the Eight Sleep was closest to the EEG for sleep stages, and the Fitbit Air was 'pretty close up there,' sometimes on par with or beating Oura and Apple Watch, which is 'amazing' for a $99 device.

Step Counting Accuracy

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The Fitbit Air and Apple Watch were 'very, very close' in step counting, while the WHOOP was slightly under. The reviewer argued Fitbit and Apple Watch are 'very good at step counting' making the $99 Fitbit a 'great step counter'.

Readiness/Recovery Score Variability

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Readiness scores varied significantly across devices. For one night, Fitbit and WHOOP both showed 90%, while Oura showed 48%. Over 11 nights, scores ranged from 55 to 80, with Fitbit sometimes 'far off' from others.

Is the Fitbit Air's heart rate tracking accurate?

The Fitbit Air's heart rate tracking is generally accurate, performing well in running comparisons against an Apple Watch and a Garmin chest strap, with an average bias of around 1-2 BPM. It showed exceptional accuracy during swimming, closely matching FORM Swim Goggles and outperforming the Apple Watch. However, it had some initial data jumping during one run and showed a 'good, not great' 2.6 BPM difference during rowing.

Does the Fitbit Air have built-in GPS for tracking runs?

The Fitbit Air does not feature an integrated GPS system. Instead, it utilizes your smartphone's assisted GPS to track distance and routes during workouts. This means you need to carry your phone with you to record GPS data.

Is the phone-based GPS good enough for casual exercise?

For casual users who want to track walks, runs, or bike rides, the phone's GPS (which the Fitbit Air uses) is 'good enough' for basic data logging. However, if you are training for a marathon or a specific race requiring highly accurate outdoor GPS for precise workout pacing, a dedicated smartwatch with multi-band GPS is recommended.

How accurate is the Fitbit Air's sleep tracking?

The Fitbit Air's total sleep duration tracking is 'pretty close' to a medical-grade EEG headband. However, specific sleep stage data, such as deep sleep, showed extreme variability between the Fitbit Air and other consumer devices when compared to the EEG headband. While the Fitbit Air can sometimes be on par with or even beat more expensive devices, the reviewer advises taking all sleep staging data with a grain of salt and not making large life decisions based on it.

Does the Fitbit Air accurately count steps?

The Fitbit Air demonstrates excellent accuracy in step counting. It performed 'very, very close' to the Apple Watch, significantly outperforming the WHOOP in this metric. The reviewer considers it a 'great step counter,' especially given its affordable price point.

Are the Fitbit Air's recovery or readiness scores reliable?

The recovery and readiness scores provided by the Fitbit Air exhibit significant inconsistency. Across multiple nights and compared to other devices like WHOOP and Oura, the scores showed drastic differences (e.g., Fitbit/WHOOP 90% vs. Oura 48% on the same night). The reviewer strongly advises against making major life decisions based on these inconsistent metrics.