I’ve seen the future, and it’s really salty: Testing Flowbio’s new wearable hydration sensor

The ‘athlete as a human machine to be optimised’ is not a new concept, but in recent years the proliferation of wearables has been frantic. The days of happily slapping on a heart rate monitor are gone; now we have power measurements, core temperature sensors, blood glucose monitors, and watches that shower you with scorn when you haven’t recovered right or got the perfect duration of sleep. 

Hydration, though, has been a relatively untapped well of data until now. Garmin has for some time had a predictive hydration feature, but it’s not based on any actual measurements. Real measurements of water loss and sodium loss have been possible but in a lab. Enter from stage left, Flowbio; a startup based in London offering a small, wearable sensor that tells you how much fluid and salt you’ve lost after your ride (or run, if that’s your cup of tea), and importantly what you can do about it.