SaltStick FastChews and Nix Biosnesor

Sweat Science

electrolytes and performance explained

Electrolytes can be the difference between finishing as a champ, or struggling with fatigue, cramping and nausea. These small but mighty elements — sodium, potassium, calcium, magnesium and chloride — play a pivotal role in muscle contraction, blood pressure, and keeping you cool (i.e sweat).

Put simply, if you're not replacing electrolytes during your training, your performance will tank.

That's all great, you might say, but I need specifics. Like, do I need more electrolytes on hot days? What about humidity? Or altitude? Do I take electrolytes before, during, or after training? How do I figure out how much water to drink?

All great questions, and like many aspects of nutrition, it depends. Everyone sweats differently. Even your own sweat rate and concentration can vary widely, depending on temperature, level of fitness, altitude, or humidity.

It can get confusing fast, so to help demystify, we followed the journey of five athletes as they dove into "Sweat Science." Each athlete tested their sweat rate, electrolyte loss rate, and sweat composition using the Nix Hydration Biosensor, which provides athletes with personalized hydration data in real time. Athletes then used their sweat data to adapt their fluid and electrolyte intake accordingly.

Check out their Sweat Science journeys below, and find out how you can use their findings and takeaways to build a knockout hydration plan.

Nix Biosensor

Thank you to Nix Biosensors for partnering with us!

The Nix Biosensor is the first biosensor to analyze sweat and provide endurance athletes with personalized hydration data -- scientifically validated and delivered in real time.

Athlete Deep Dive: Danielle Lao

Sport: Tennis

Skill Level: Professional

Self-Proclaimed Light Sweater

Quote: The Sweat Science campaign was really eye-opening for me because it challenged some of my preconceived notions about sweat…” says Danielle. “When I cycle indoors, I feel like I flood the house with sweat and have to canoe myself out of the room. And I thought surely that I lose way more water on the trainer than in other sweat tests, but the numbers showed that I actually sweat less during indoor cycling workouts than during outdoor runs.”

Danielle Lao

Danielle's Key Takeaways

1. Not only do I sweat more in the heat, but my sweat composition is also saltier in the heat.

2. I lose significantly more electrolytes on speed workout days vs. easy run days.

3. I actually sweat less during indoor rides than during most runs and tennis workouts.

Click the video on the left to watch Danielle's full interview!

How Danielle Applies Her Learnings

1. I now pre-load on electrolytes with a Race Ready Cap Plus before hot workouts. The electrolytes top off my hydration stores, and the caffeine gives me a boost of energy to get through it.

2. Since my sweat is saltier in the heat, I now take two FastChews during each tennis breaks instead of one.

Other Athletes

Stay tuned to follow results from their hydration journeys as well!

Taggart VanEtten
Nikkia Raedawn
Ben Hoffman
Screenshot of SaltStick YouTube videos.

Watch Our Sweat Science YouTube Series

Throughout the campaign, we checked in with each athlete via Instagram Live chats. We invite you to check them out!

Episode 1: Kickoff Session IG Live with Nix Biosensors

Episode 2: Live with World Record Ultrarunner Taggart VanEtten

Episode 3: Live with Pro Tennis Player Danielle Lao

Episode 4: Live with Certified Run Coach Nikkia Raedawn

Episode 5: Live with IRONMAN Champion Ben Hoffman

Check Out Our YouTube Channel

Nix Hydration Biosensor

Recommended for workouts of 45 minutes or longer, our lightweight durable hydration monitor quantifies when, what, and how much to drink (water or electrolytes) while analyzing your sweat moment-to-moment. The rechargeable pod clips onto a single-use sweat patch before the start of each workout to read and transmit data to the Nix app. It integrates with your smartphone or watch to deliver personal hydration data in real time providing hydration intelligence to improve your athletic performance, safety, and wellbeing.


Nix Hydration Biosensor Starter Pack

Sweat Patch Refills

Nix Sweat Patch Refills include four single-use sweat patches to be used in conjunction with the reusable Pod before each new workout. The Sweat Patch sticks to the bicep via adhesive and is completely non-invasive. We recommend wearing a patch during a sweat inducing workout, ideally running or cycling, lasting at least 45 minutes in duration. After your run or ride is complete, a post-workout summary in the Nix App provides intel that can help inform your hydration strategy going forward.


Nix Biosensors Refill Pack