The Coospo Realzone H9Z may be a no-frills heart rate monitor, but it’s cheap, reliable and has a useful rechargeable battery upgrade over its H808S stablemate.

A good option for pairing with the best rowing machines or exercise bikes, the Coospo Realzone H9Z offers a compact design, a rechargeable battery, and excellent value for money. Here’s how it performed on test.

Coospo Realzone H9Z

Best for easy recharging

Close up of a man's hand holding a Coospo heart rate monitor

$49.90 / £36, coospo.com

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Pros:

  • Rechargeable battery
  • Excellent value

Cons:

  • Tracking limited to BPM
  • No built-in memory

Comfort: 4/5
Accuracy: 4/5
Tracking features: 2/5
OVERALL: 4/5

The Coospo Realzone H9Z chest strap offers much the same basic set-up as its slightly cheaper stablemate, the no-frills Coospo H808S. But there’s one big difference: it swaps the classic chest strap coin-op battery for a rechargeable sensor with its own USB dock.

Coospo Realzone H9Z features

One of the best heart rate monitors on test, the H9Z sensor is lighter, more compact and a shade more comfortable than the H808S. Everything else is largely the same. That includes good, reliable connectivity with ANT+ and Bluetooth 5.0 and support for two simultaneous connections to your favourite fitness machines, apps and fitness watches. 

The Coospo Realzone H9Z is IP67 rated so it’ll handle sweat and rain – and being submerged in a metre of water. But it’s not suitable for swimming. Like the H808S there’s no onboard memory either. So you can’t track and store workouts independently, then sync later. 

The strap is pretty standard. It’s not as soft as some chest straps but still perfectly comfortable. In testing, I wore it for up to three hours at a time, plus lots of dynamic gym sessions, and had no problems with rubbing, chafing or cutting. 

Coospo Realzone H9Z tracking

In terms of tracking, there are no frills here. The H9Z clocks heart rate, heart rate variability and calories and offers zone training alerts via the partner app. But there’s no additional smarts like running form tracking, step counting or the bells and whistles you find on pricier straps like the Garmin HRM Pro Plus.

There are some really helpful touches, though. When you connect the sensor, it beeps to let you know it’s working. All HRMs should do this. There’s also a five-colour LEDs on the sensor so you can see what zone you’re working in. But that’s only useful if you’re training with your shirt off. 

I found its accuracy to be solid. In tests, the H9Z matched the £400 Frontier X2 and the most accurate arm strap HRM – the Polar Verity Sense – almost beat for beat. The highs, lows and averages were a close match too. 

Battery life is also good. On paper you get up to 50 hours standby and approximately 32 hours training time on a single charge. In my tests, the battery life was barely touched, even after a two-hour session.

This is a simple but functional heart rate monitor. If all you want is your heart rate beamed to your watch, bike computer, training platform or fitness app, the Cosspo Realzone H9Z offers excellent bang for your buck.