Every feat of my heart

Whoop's screen-less fitness tracker adds a medical-grade ECG and blood pressure estimates – but the subscription isn't cheap

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£349/yr /go.

stuff.tv/Whoop

The Whoop MG can track just about everything, but its bread and butter is strain – your total exertion each day. This affects your recovery score, and the two are combined to give your optimal strain target for the day. It detects activity automatically, but I did find that some shorter bursts slipped through the net.