First-generation product — no historical cycle data to predict a successor
Full details →| Fitbit Air | Polar Grit X | |
|---|---|---|
| Pricing | ||
| Starting price | $99★ | $749 |
| Subscription | ℹ️ Optional — $99/yr | ✓ None |
| Hardware | ||
| Weight | 12g★ | 57g |
| Water resistance | 50m | 100m★ |
| Battery | 7 days | 40 days★ |
| Always-on display | ❌ | ❌ |
| GPS | ❌ | ✅★ |
| Cellular | ❌ | ❌ |
| Platform | iOS & Android | iOS & Android |
| Tier | Fitness Tracker | Sports GPS |
| Buy timing | ||
| Released | May 7, 2026 | Apr 11, 2024 |
| Cycle advice | good★ | bad |
| Deals advice | good | good |
| Next model | — | — |
Unlike WHOOP, there is no mandatory membership — pay $99 once and use Fitbit Air with the free Google Health app. Google Health Premium ($9.99/month) is optional.
Continuous heart rate, SpO2, HRV, and skin temperature tracking plus background FDA-certified AFib detection, in a 12g pebble designed to be worn and forgotten.
A week between charges, with a 5-minute top-up delivering a full day of use — significantly less downtime than WHOOP's slide-on charging system.
Five times the battery of the Vantage V3 — enough for week-long mountain stages or ultramarathons without charging access.
Automatically segments your run by uphill and downhill sections, calculating pace and power for each — essential for mountain race training.
Running power without a chest strap or foot pod — Polar's key differentiator versus Garmin at this price tier.
The right pick depends on what you optimize for.
$396 vs $749 over 3 years · no required subscription.
40 days vs 7 days battery.
5 sensors · 0.5 Hz HR sampling.
12g · no required subscription.
Health-focused users who want passive, 24/7 biometric tracking without a screen on their wrist. Particularly strong for those drawn to WHOOP but put off by the subscription model — the Fitbit Air delivers comparable core health data for $99 outright. Works with both iOS and Android.
Full details →Trail runners, hikers, and outdoor athletes who want Polar's analytics with significantly longer battery life than the Vantage V3. The titanium case and sapphire glass make it suitable for technical terrain where watch durability matters.
Full details →