Wearable-Agnostic Fitness Tech: Apple, Garmin, WHOOP, Myzone, Polar & the New Garmin CIRQA

Walk any gym floor and count the wrists. Apple Watches, Garmins, the odd WHOOP band under a sleeve, a Polar strap or two, a Myzone belt from the last place someone trained. Your members and clients have already spent their own money on the hardware. The question is no longer whether they have a wearable. It is whether your software can talk to all of them. That is the whole case for a fitness app that connects any wearable, rather than one that locks you and everyone you train into a single brand.

Most fitness tech was built the other way round. Buy our band, sell our band, replace our band. It made sense when a gym had to own the sensors, but it quietly punishes everyone who already owns a perfectly good device. This post is about the wearable-agnostic approach: reading heart rate and effort from whatever your people already wear, and letting the software do the work that used to need a shop full of hardware.

Why brand lock-in is the wrong default

A single-brand system looks tidy on paper. In practice it creates friction at exactly the wrong moment. Every new member or client becomes a small sale before they can take part, because the live board only reads the device you stock. Owning the wrong brand means sitting the session out or buying a second gadget for the wrist that already has one.

There is a cost problem too. Belts and bands wear out, get lost and need reordering. Somebody has to stock them and sanitise them between classes. For a gym that is an equipment business bolted onto a training business. For a coach it is worse, because you cannot realistically post a chest strap to every client and expect it back.

A system that simply reads whatever wearable already walked in removes all of that. There is nothing to sell before someone can join in, nothing to reorder, and nobody locked out for owning an Apple Watch when the system was built around a belt. If you have been comparing this directly against a belt-first setup, we have laid out the trade-offs in the best Myzone alternative for gyms.

What "wearable-agnostic" actually means

Being hardware-agnostic describes something concrete. The software reads the same underlying heart rate signal no matter which device broadcasts it, so the brand on the wrist stops mattering.

The devices that already work

Fittest is software-only and hardware-agnostic. Members and clients connect the wearable they already own:

• Apple Watch reads heart rate straight off the wrist.
• Android watches broadcast the same signal.
• Garmin works across its range, and Fittest is an official Garmin partner. That partnership includes the new screenless Garmin CIRQA band, built to do one job well: read effort and send it on, without a display to distract from the session.
• WHOOP and Myzone both connect, so the kit people already trust carries over.
• Polar and most standard HR belts round it out, so a plain chest strap is never left out.

The point is that this is not a list your members have to shop from. It is a list of what they already have. The gym or coach provides the software; the wearable is whatever walked in the door.

The gym's side: no hardware in the wall

For a gym, agnostic also means nothing to mount. Live heart rate, effort points and leaderboards go up on any TV, across as many screens as you like, with no receivers or sensors in the building. A member connects their watch and appears on the board. We have written a full walkthrough of that setup in live heart-rate leaderboards and class energy.

Reading the whole wearable, not just a pulse

Connecting to any device is only half the story. The other half is doing something useful with what those devices measure, and modern wearables measure a lot more than beats per minute.

Because Fittest reads the full picture, the same connection powers a Daily Recovery Score, weighted from HRV, sleep, VO2 max and resting heart rate. Above 75 is optimal, 50 to 74 is fair, and under 50 is a clear signal to recover rather than grind. That turns the watch into a coaching input, not just a leaderboard feed. We go deeper on what those numbers mean and how to act on them in recovery scores explained.

There is also Live Pace, a Weekly Summary, 90-day Personal Bests, Workout Comparison and a simulation feature for race formats like HYROX, plus a Strava connection. None of that needs a special device. It needs a wearable-agnostic layer that knows how to read whatever is already on the wrist.

Scoring effort fairly across devices

Raw heart rate quietly rewards one kind of training and punishes another. A heavy lifter can work brutally hard and barely move their pulse, then finish bottom of a cardio-weighted board. Fittest scores strength to the same standard as HIIT and cardio, so the lifter and the runner compete on effort rather than on which movement happens to spike a heart rate. That fairness matters even more when the devices differ, because it means the person on a chest strap and the person on a wrist optical sensor are measured on the same terms.

What this means for coaches

Wearable-agnostic tech is not only a gym-floor feature. For personal trainers and online coaches, whose clients are rarely in the same room, it is the only realistic way to see effort and recovery at all. You cannot mount a screen in someone's spare bedroom. You can, however, read the Apple Watch or Garmin they already train in.

That connection sits underneath the wider Fittest coaching stack: AI programme delivery and building, 1RM percentage-based programming, an exercise video library you can add your own clips to, AI meal plans and food logging, AI Body Analysis from a photo, habit tracking, and 1:1 and group chat with video. An AI Assistant is on the way too, designed to run check-ins, watch client data and surface insights like a second version of you. The wearable data feeds all of it, which is only possible because the platform does not care which wearable it is.

How Fittest helps

Fittest is the software layer that turns whatever your members and clients already wear into live effort, recovery and progress. It is software-only and hardware-agnostic, so there is no gym hardware to buy and no belts to sell. Apple Watch, Android watches, Garmin including the new screenless CIRQA band, WHOOP, Myzone, Polar and most HR belts all connect and feed the same system.

For gyms, that means live heart rate, effort points and leaderboards on any TV with no hardware in the wall, plus Strength Scoring, the ranking ladder that banks effort into a long-term chase, Daily Recovery Scores, Personal Bests and a simulation feature for HYROX-style events. Pricing is a flat monthly fee per location, not per member: Starter up to 100 members at £100 a month, Build up to 200 at £150, Growth up to 500 at £200, and Enterprise for larger sites. Pay yearly and get three months free.

For coaches, the same wearable-agnostic core sits under the full Pro stack, which bundles everything in a single add-on rather than a shelf of separate tools. Either way, the sensors are already on the floor or on the wrist. The retention and coaching value comes from software that reads all of them, which is also why fewer members quietly drift away, a loop we cover in how to reduce gym member churn.

The best wearable is the one your people already own. Book a Fittest demo and we will show you how their existing devices, whatever the brand, become live effort and real coaching data.