# Polar Loop with Keely, or WHOOP.

> https://meetkeely.com/compare/whoop · Updated 2026-09-28 · Keely, by Metrica Fit LLC

**Both give you a Recovery score from 0 to 100 % each morning, a measure of the day’s effort, and sleep against your need.** WHOOP is a membership, from $199 a year with the band included. A Polar Loop is $199.99 once, and Keely is free. WHOOP measures more, including blood oxygen; Keely publishes every formula and keeps your raw heart data on your iPhone.

## At a glance

| | Polar Loop with Keely | WHOOP 5.0 and MG |
|---|---|---|
| Price (US) | $199.99 for the Loop, once. Keely is free | A membership with the band included: One $199, Peak $239 or Life $359 a year |
| Subscription | None | Required. New members choose 12 or 24 months |
| Morning score | Recovery, 0–100 %: Primed, Balanced or Restore | Recovery, 0–100 %: green, yellow or red |
| What it weighs | HRV, resting heart rate, sleep, breathing rate and skin temperature | HRV, resting heart rate, sleep performance, respiratory rate, blood oxygen and skin temperature |
| Effort | Load: points per minute by heart-rate zone, linear with no ceiling, and a target range each morning | Strain: 0–21, logarithmic by design, from heart-rate zones and muscular load |
| Stress | Live, 0–100, scored only while you’re still | Stress Monitor, 0–3, on Peak and Life |
| Sleep | Stages from the Loop, need (goal, debt and a hard day), consistency and a lights-out time | Sleep performance, need (baseline, strain, debt and naps), consistency |
| Formulas | Every input, weight and constant is published | Inputs are described; WHOOP says the weights aren’t published |
| Sensors | Optical heart rate, accelerometer, skin temperature | Adds blood oxygen; WHOOP MG adds an ECG |
| Battery, by the maker | Up to 8 days (Polar’s figure, with Polar Flow) | 14+ days |
| Alarm | None: the Loop can’t vibrate | Haptic alarm |
| Your data | Raw heart data stays on your iPhone; your account backs up daily summaries | Stored in your WHOOP account, with a CSV export and a developer API |

Facts about WHOOP come from WHOOP’s own pages, checked September 28, 2026. This page compares cost, scores and data; it doesn’t test sensor accuracy.

## Cost over two years

At today’s US prices, with no discounts:

| | First year | Two years |
|---|---|---|
| Polar Loop with Keely | $199.99 | $199.99 |
| WHOOP One | $199 | $398 |
| WHOOP Peak | $239 | $478 |
| WHOOP Life | $359 | $718 |

## Where WHOOP does more

- **More sensing.** Blood oxygen on every tier. WHOOP MG, on the Life tier, adds an FDA-cleared ECG (Heart Screener) and Blood Pressure Insights.
- **A haptic alarm.** The Loop has no vibration motor, so it can’t wake you silently.
- **Battery.** 14+ days, and on Peak and Life a PowerPack that charges the band on your wrist.
- **More features.** Healthspan (WHOOP Age), AI coaching, a strength trainer and hormonal insights.
- **Your data, out.** A CSV export and a developer API. Keely doesn’t export yet.
- **Where you wear it.** WHOOP’s sensor also fits its own garments and a bicep band.

## Where Keely is different

- **No subscription.** You buy the Loop once, and Keely is free.
- **Every formula is public.** Recovery’s weights, Load’s points and every constant are on the [methodology page](https://meetkeely.com/methodology), so any number can be checked.
- **Load has no ceiling.** WHOOP describes Strain as logarithmic: two workouts of 10 don’t add up to 20. Keely’s [Load](https://meetkeely.com/load) is linear, so twice the work is twice the Load, and each morning brings a target range set by your Recovery.
- **Stress from 0 to 100, day and night.** Live from the Loop while Keely is open, and never scored while you move. See [Stress](https://meetkeely.com/stress).
- **Your raw heart data stays on your iPhone.** Only daily summaries are backed up to your account.

## Frequently asked questions

### Is the Polar Loop with Keely a WHOOP alternative without a subscription?

Yes. You buy the Loop once, and Keely turns it into a morning Recovery score, a Load target, live stress and sleep against your need, free. WHOOP includes its band in a membership that starts at $199 a year.

### Is Keely’s Recovery the same as WHOOP’s?

Both run from 0 to 100 % and both lean on HRV and resting heart rate, but they’re different calculations, so the numbers won’t match. Keely’s weights and formula are on its [Recovery page](https://meetkeely.com/recovery).

### Is Load the same as Strain?

No. Strain runs from 0 to 21 on a logarithmic scale, so each point is harder to earn than the last. Load counts every minute by its heart-rate zone with no ceiling: an hour in Zone 2 is about 120, and three hours about 360.

### Can I use my WHOOP band with Keely?

No. Keely works with the Polar Loop.

### Can I bring my WHOOP history to Keely?

Not yet. Keely starts fresh: it learns your normal over your first nights, and your first Recovery arrives after 3.

## Sources

- WHOOP membership and prices: [whoop.com/us/en/membership](https://www.whoop.com/us/en/membership/), and [Membership Pricing](https://support.whoop.com/s/article/Membership-Pricing?language=en_US) (May 28, 2026).
- WHOOP 5.0 and MG: [WHOOP’s launch announcement](https://www.whoop.com/us/en/press-center/whoop-unveils-5.0-MG/), May 8, 2025.
- Strain’s scale, and that its formula isn’t published: [How does WHOOP Strain work?](https://www.whoop.com/us/en/thelocker/how-does-whoop-strain-work-101/)
- Recovery’s inputs: [WHOOP 101](https://developer.whoop.com/docs/whoop-101/).
- Stress Monitor: [Get to know the Stress Monitor](https://support.whoop.com/s/article/Get-to-Know-the-Stress-Monitor?language=en_US).
- Data export: [How to export your data](https://support.whoop.com/s/article/How-to-Export-Your-Data).
- Polar Loop price: [Polar’s US store](https://www.polar.com/us-en/loop). Specifications: [Polar Loop user manual](https://support.polar.com/e_manuals/polar-loop/polar-loop-user-manual-english/technical-specifications.htm).

All checked September 28, 2026. Prices and features change, so check WHOOP’s before you buy. WHOOP is a trademark of WHOOP, Inc.; Keely isn’t affiliated with or endorsed by WHOOP or Polar.

## Keep reading

- [Oura](https://meetkeely.com/compare/oura): The Polar Loop with the free Keely app, compared with the Oura Ring: cost, Readiness and Recovery, stress, sleep, sensors and data. Checked September 28, 2026.
- [Polar Flow](https://meetkeely.com/compare/polar-flow): Two free apps for the same band. How Keely compares with Polar Flow for the Polar Loop: Recovery and Nightly Recharge, Load, stress, sleep, data and switching.
- [Recovery](https://meetkeely.com/recovery): Keely’s Recovery is a 0–100 % score each morning: last night’s HRV, resting heart rate, sleep, breathing and skin temperature against your own normal.

Keely is coming to the App Store for iPhone (iOS 26 or later). Need a Polar Loop? https://meetkeely.com/loop (an affiliate link: as an Amazon Associate, Metrica Fit earns from qualifying purchases).