Trusted Reviews is supported by its audience. If you purchase through links on our site, we may earn a commission. Learn more.

Polar Grit X offers insane 40-hour battery life with everything enabled

Polar has revealed its new Grit X will test the limits of the most ardent ultra runners with a battery life that’ll last for 40-hours, even with all of the keys features turned on.

The brand new multi-sport Grit X watch brings built-in GPS, heart-rate tracking, barometer, compass and an altimeter, as well as all of the Polar Flow smart couching tools, can all be enabled without risk of the battery conking out within hours.

In watch mode you’ll get 7 days of battery life with continuous heart rate monitoring, while one of the power saving modes will give you 100 hours while using training features.

The Grit X is loaded with useful training tools including a neat Hill Splitter feature which uses the altitude to show how you performed in uphill and downhill stages of your workout.

Running Index estimates your running VO2max, while route guidance brings turn by turn directions into play. You can also benefit from the FuelWise tool, which offers advice on how to refuel during the training run/ride. There’s weather forecasts, sleep and recovery tracking, calorie counting, breathing exercises, running power, fitness tests and much more.

Related: Best running watches 2020

The lightweight (64g and 44g without wristband) Grit X watch doesn’t scrimp in the durability stakes either. The stainless steel case is complemented by a Gorilla Glass display (full-colour display is 1.2-inches with a 240 x 240 resolution) and has passed several of the MIL-STD-810G tests against drop tests, temperatures and humidity. It’s also water resistant to 100m.

Thanks to Bluetooth LE compatibility the Grit X is “compatible with all standard BLE heart rate sensors and running cadence and power sensors as well as cycling speed, cadence and power sensors.”

The Polar Grit X is available to buy today in the UK from £379 in black & black and green & silver shades. There’s also a host of wristbands options starting at £26.50.

Why trust our journalism?

Founded in 2004, Trusted Reviews exists to give our readers thorough, unbiased and independent advice on what to buy.

Today, we have 9 million users a month around the world, and assess more than 1,000 products a year.

author icon

Editorial independence

Editorial independence means being able to give an unbiased verdict about a product or company, with the avoidance of conflicts of interest. To ensure this is possible, every member of the editorial staff follows a clear code of conduct.

author icon

Professional conduct

We also expect our journalists to follow clear ethical standards in their work. Our staff members must strive for honesty and accuracy in everything they do. We follow the IPSO Editors’ code of practice to underpin these standards.