https://www.polar.com/us-en/grit-x-pro

Price: $499.95

Description:

Know if you’re training too much, too little or just right: improve your performance, prevent injury.

Automatically track the quality and duration of your sleep, and see how long you spent in each sleep stage overnight.

Maximize your training and recovery with Polar Training Tests. Access all the data you need to check the condition of your body, calculate your performance, track your progress and personalize your training zones. Access the hidden data you need to see when your body is fully recovered.

Play the music you love

Check the weather

And more!

The SELF Institute