24 hours.

The electronic pod is durable, reusable and built to last. The pod clips onto a single-use sweat patch. A new patch should be worn for each workout.

The biosensor connects to a single-use patch that adheres to the bicep. On the back of the patch there is a channel with two sets of electrodes spread apart. As your sweat moves through the channel, your sweat rate is calculated based on the amount of time it takes your sweat to travel between the first and second set of electrodes. The data is sent from the biosensor to your phone, watch or bike computer.

The sensor itself comes with a charger case, it is reusable and built to last. The sensor attaches to a separate sweat patch that sticks to your arm, the patches are disposable and are meant to be single-use only.

Yes. The only thing to be aware of is if the clothing is extremely tight or if you expect you'll pull the sleeves up and down a lot during the workout, as it could pull at the sensor such that it would fall off your arm.

Sunscreen, bug spray, lotion, etc. can all interfere with the sensor's readings if they get mixed into the sweat. To mitigate that, we recommend those items get applied after the sensor is applied, as the sensor will seal off the outside environment.

No. The sensor clips onto a disposable patch that sticks to the surface of the skin via adhesive. It is completely non-invasive.


The Nix app will provide you with total fluid loss, sweat rate, total electrolyte loss, electrolyte loss rate, and sweat composition after each workout. Live notifications are available within the app and preferences can be personalized based on the athlete or workout. The Nix Index will also be shared for a given day and be listed beside each previous workout.


Your phone is required to be with you during a workout if you'd like to receive live updates about your fluid loss and hydration suggestions. If you don't want to carry your phone with you during your workout, you will not receive live updates, but you will be able to have full access to review your data afterwards.


We are initially launching with Apple watch, Garmin watch, and Garmin bike computer integrations. We have many more integrations on our list that will come in the near future.

D2™ Delta

D2™ Delta PX

D2™ Delta

Svívoactive® 3 Music LTE

Darth Vader™

Descent™ Mk2 / Descent™Mk2i

Descent™ Mk2 S


fēnix® 5 / quatix® 5

fēnix® 5X / tactix® Charlie

fēnix® 5 Plus

fēnix® 5S Plus

fēnix® 5X Plus

fēnix® 6 / 6 Solar / 6 Dual Power

fēnix® 6S / 6S Solar / 6S Dual Power

fēnix® 6 Pro / 6 Sapphire / 6 Pro Solar / 6 Pro Dual Power / quatix® 6

fēnix® 6S Pro / 6S Sapphire / 6S Pro Solar / 6S Pro Dual Power

fēnix® 6X Pro / 6X Sapphire / 6X Pro Solar / tactix® Delta Sapphire / Delta Solar / Delta Solar - Ballistics Edition / quatix® 6X / 6X Solar / 6X Dual Power

fēnix® 7

fēnix® 7S

fēnix® 7X

First Avenger

Forerunner® 245

Forerunner® 245 Music

Forerunner® 645

Forerunner® 645 Music

Forerunner® 745

Forerunner® 935

Forerunner® 945

Forerunner® 945 LTE

MARQ® Adventurer

MARQ® Athlete

MARQ® Aviator

MARQ® Captain / MARQ® Captain: American Magic Edition

MARQ® Commander

MARQ® Driver

MARQ® Expedition

MARQ® Golfer

Venu® Sq

Venu® Sq. Music Edition


vívoactive® 3 Music

vívoactive® 4

Series 3 or newer


We are initially launching within the USA. We're hoping to expand to additional countries in the future. Stay tuned!