Massachusetts-based Nix has launched a biosensor that analyses sweat and provides endurance athletes with real-time personalised hydration data.

Proper hydration is critical to endurance athletes’ performance and safety. The impacts of dehydration range from mild (fatigue and muscle cramping) to severe (organ failure and death). Studies show that when athletes drink to thirst, they’re replenishing only half of the fluids they’ve lost, incurring mild dehydration up to 80% of the time.

Hydration management is further complicated by the wide range of variability in an individual’s sweat rate, due to myriad factors such as temperature, humidity, altitude and workout intensity.

With hydration intelligence, athletes no longer need to leave proper hydration to chance and can make informed decisions based on their sweat profile.

“Athletes are acutely aware of the importance of proper hydration for performance and safety, but have never had the proper tools until now,” said Meridith Cass, CEO of Nix. “Nix eliminates the traditional trial-and-error approach to hydrating; athletes can now get precise, personalised hydration metrics, telling them exactly when, what and how much to drink.”

The sensor sends real-time data to the Nix app, which integrates with iOS devices and Garmin sport watches, with Android and Garmin bike computer compatibility coming soon. By sharing in-the-moment, actionable notifications on fluid and electrolyte loss, athletes can perform at their peak.

A single-use patch comfortably adheres to the body to collect and analyse sweat. It sticks to the surface of the skin with kinesiology tape for flexible comfort and continuously evaluates fluid and electrolyte losses once the wearer starts sweating.

A durable, reusable pod clicks into the single-use patch to read and transmit data to the Nix app. It weighs 14g and is similar in size to a sports watch face. The battery life lasts up to 36 hours and it streams real-time data to the Nix app.

The free app provides real-time hydration intelligence and helps users prepare for their next run or ride. It provides real-time hydration notifications and post-workout hydration summaries.

In the future, Nix intends to expand connectivity to additional platforms such as Strava, Wahoo, TrainingPeaks, Zwift, Suunto and Coros.

Nix’s hydration intelligence doesn’t just help increase performance and recovery, it gives a new way to access, understand and act on the wearer’s personal biology so they can make better decisions in real time. Wearers can see how their sweat composition changes based on internal and external factors and identify the right hydration products for their needs.

Before a workout begins, the wearer tells the app what type of workout they are doing, such as running or biking, whether indoors or outdoors, and what they are planning on drinking, either water or they can select an electrolyte drink from the dropdown menu. They can also select notification preferences, for example choosing to receive hydration notifications based on time elapsed or fluid lost.

Once they start sweating, which can take up to 25 minutes, the patch begins measuring and analysing fluid and electrolyte losses per hour, metrics that represent a unique sweat composition.

These data are instantly streamed to the app, and can be shared with devices such as an iPhone, Apple Watch, Garmin Watch and Garmin bike computer.

After the run or ride is complete, a post-workout summary provides intelligence that can help inform the wearer’s hydration strategy going forward. They can also access a list of hydration products organised by electrolyte composition and identify the option that best matches their needs.

While launching in endurance sports, Nix is already conducting research pilots in team sports, military, and labourer populations and plans to expand in some of these markets as early as 2023.

Headquartered in Boston, Massachusetts, Nix is led by founder and CEO Meridith Cass, a graduate of Harvard Business School and a nine-time marathoner. Advisors include Tom Fowler, former president of Polar; Bob Murray, founder and former director of the Gatorade Sports Science Institute; and Tatyana McFadden, a five times Olympian and 17 times medallist.