Heart rate monitors

Polar H10 hartslagband

The Polar H10 is a heart rate strap from Polar. The title is bare, but the model is known as a chest strap for heart rate measurement.

What you get

Polar H10 heart rate strap
Model H10

Why a heart rate monitor?

Your heart rate is a direct measure of how hard your body is working. With zones, you ride easy endurance rides truly easy and hard intervals truly hard. Many cyclists ride their easy days too fast and their hard days too soft. A heart rate monitor helps you correct that.

There are two ways to measure. A chest strap reads the electrical signals of your heart, like an ECG, and so lands very close to the true value. It responds within a few seconds of an effort. An optical sensor shines light into your skin and measures blood flow (PPG). That works well at steady effort, but often lags 10 to 30 seconds behind on short intervals and can drift with a loose band, cold hands, a tattoo, or a rhythm that matches your pedalling cadence.

An optical sensor on the upper arm or forearm is usually more accurate than one on the wrist, because it sits more steadily and moves less. A wrist watch is the easiest for everyday use, but the most sensitive of the three when it comes to measurement.

Heart rate does not say everything. Heat, caffeine, sleep, stress and even a poor night push your numbers up or down. Treat it as a guide and look at the whole picture over several days.

Chest strap versus optical

All three measure your heart rate, but in different ways.

Type	Accuracy	Response	Comfort	Best for
Chest strap	Very high, close to ECG	Within a few seconds	Noticeable, elastic round the chest	Intervals, racing, training
Optical on the arm	High, just below the chest strap	About 5 to 15 seconds	Good, no chest strap	Endurance rides, no strap wanted
Optical on the wrist	Fair, more sensitive to disturbance	Often 10 to 30 seconds behind	Very good, worn all day	Everyday use, steady riding

A guide. Fit, skin and temperature strongly affect optical readings.

Choose it if

You want to measure heart rate with a chest strap from a known brand
You pair it with a bike computer or an app
You want to train in zones and time intervals exactly: choose a chest strap.
You want something easy to wear that you forget about: choose an optical armband.

Choose something else if

You want a wrist or arm sensor
You ride rarely and feel is enough. A heart rate monitor adds little then.
You have a heart condition or take medication that affects your pulse. Ask your doctor how best to use the numbers.

How to use a heart rate monitor

Moisten the skin
Wet the electrodes of a chest strap with water or electrode gel. Dry skin gives an erratic or missing signal.
Wear it in the right place
Wear a chest strap snug below the chest. An armband goes on the upper arm or forearm, a watch about a finger-width above the wrist.
Pair with your device
Search for the sensor over ANT+ or Bluetooth on your bike computer or in your app. Check that a number shows up within a few seconds.
Set your zones
Use your maximum or threshold heart rate from a test to set zones. The formula 220 minus age is only a rough estimate.
Ride and clean
Rinse the strap with lukewarm water after each ride and let it dry. Take the pod off before washing it.

Good to know

The title lists no connections or strap size, so read the product page
Check that your device supports the strap's connection
A chest strap wears out: the elastic loses tension and the electrodes age, usually after a year or two of heavy use.
The battery in a strap typically lasts a full season or more. Replace it if the signal turns erratic.
Optical sensors give less reliable readings in cold weather and under tight gloves.
Check that the sensor supports both ANT+ and Bluetooth, so it works with your computer and your app.

What you get

Why a heart rate monitor?

Chest strap versus optical

Choose it if

Choose something else if

How to use a heart rate monitor

Moisten the skin

Wear it in the right place

Pair with your device

Set your zones

Ride and clean

Good to know

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