One great deal we’ve found today is on the immensely useful Fitbit Charge 6 fitness tracker. This handy device can be a huge boon for your health, and while it’d normally set you back $160, this Prime Day deal knocks it down by 38% to just $100.

From telling you how fast you are “ageing”, to giving you a sleep score and even keeping tabs on your blood pressure — fitness trackers and smart watches are more focused on health than ever.

You get just about every possible health metric from the Whoop MG, but it's auto-detection lets it down. How does it fare overall?