Hydration advice for runners has long been based on averages, assumptions, and trial-and-error. But what if you could actually see your sweat and electrolyte losses in real time?

In this episode, I’m so excited to be joined by Meridith Cass, Founder and CEO of Nix Biosensors.

Meridith Cass is the Founder and CEO of Nix Biosensors, a pioneering health tech company that developed the world’s first consumer-ready biosensor for real-time hydration monitoring. Under her leadership, Nix has been recognized by TIME's Best Inventions, Runner’s World Gear of the Year, and the CES Innovation Awards, and is transforming how athletes, military personnel, and everyday consumers manage hydration and performance. Prior to founding Nix, Meridith held leadership roles in healthcare and venture-backed startups, and earned her MBA from Harvard Business School. She is a passionate advocate for personalized health, data-driven recovery, and the future of wearable biosensing.

In this episode, we cover:

• The origin of Nix Biosensors and how a marathon experience led Meridith Cass to rethink hydration and electrolyte guidance

• How the Nix Biosensor works, what it measures, and why real-time sweat data is a game-changer for athletes

• Who sweat testing is most useful for, what athletes can realistically learn from their data, and common mistakes in interpretation

• How to turn sweat and sodium data into a practical hydration plan for training and racing

• The future of hydration science and how wearable biosensing could change the way everyday runners fuel and perform.

  
  

  Looking for the resources mentioned in today's episode?

  ⁠⁠⁠⁠⁠Get your free fueling audit here!⁠

  
  Curious what your sweat data looks like?
  Get 15% off the Nix Biosensors using my exclusive promo code SHNATIUK15.

  Learn more and grab yours at nixbiosensors.com

  If you’re tired of guessing your hydration and electrolyte needs, this is one of the most powerful tools you can add to your training toolbox.

Welcome to Season 4 of the Fuel Run Recover Podcast!
Whether you’ve been here since Season 1 or you’re brand new, I’m so glad you’re listening.

To kick off this season, we’re starting with a controversial question I see all over social media:
Should women stop running?

Short answer: No.
Longer answer: let’s talk about why people say this, where the hormone fear-mongering comes from, and what actually matters for women’s health.

In this episode, we cover:

• The long history of women being discouraged or banned from running

• Why outdated beliefs about women’s bodies still show up today

• Claims about cortisol, hormones, and running, and what the science really says

• Why underfueling and poor recovery are the real issues, not running itself

We break down how problems like missed periods, fatigue, weight changes, and burnout are most often linked to low energy availability, not running as a sport. Running isn’t “bad” for women, it just needs to be supported with adequate fuel, rest, and recovery.

If you love running, keep going.
If you don’t love running, it’s okay to choose something else.
And if you’re unsure whether your training and nutrition are truly supporting your health and performance, I’d love to help.

Looking for the resources mentioned in today's episode?

⁠⁠⁠⁠⁠Get your free fueling audit here!⁠

And if you’re ready for more support, I’ve got options—whether it’s my brand-new ebook⁠ ⁠Fuel Smarter, Run Stronger⁠⁠, my group program⁠ ⁠The Fuel Train Recover Club,⁠⁠ or apply for limited spots in my personalized⁠ ⁠1:1 coaching ⁠⁠programs.

Today we're talking about fueling for short workouts and races, yes even if you don't technically 'need to'.

There’s a trend I keep seeing online—runners bragging about how little they fuel or hydrate during long runs or races, flexing about fasted workouts, and downplaying the need for carbs or hydration. Even some running books and coaches still promote training in a glycogen-depleted state.

So in this episode, we’re unpacking it all. You’ll learn why some runners are drawn to the "no fuel, no hydration" mentality, and why others prioritize performance, enjoyment, and longevity in the sport. Spoiler alert: it’s not about who’s right or wrong—it’s about different perspectives, beliefs, and goals.

As a running coach and dietitian, I’m here to break down why fueling—even for workouts or races you technically could complete without it—can be a total game-changer for performance, recovery, and enjoyment.

In this episode, I cover:

-Why some runners love “the grind” and prefer to train or race with as little support as possible

-A contrasting mindset: optimizing performance and enjoying the experience-The science behind why carbs improve performance in endurance sports

-Why hitting the wall, walking the last few miles, or constantly bonking could be a fueling issue

-How under-fueling can negatively impact muscle mass and body composition

-The importance of gut training during your workouts—not just on race day

-The truth about fasted training and glycogen depletion

-Why even short races like 10Ks and half marathons can benefit from fuel and hydration strategies

-Practical reasons to fuel during training (gear, logistics, GI practice, etc.)

Whether you’re newer to running or a seasoned pro, this episode will help you reflect on your approach to fueling and why the “just because I can doesn’t mean I should” mindset might be worth exploring.

Looking for the resources mentioned in today's episode?

⁠⁠⁠⁠⁠⁠⁠Get your free fueling audit here!⁠⁠⁠

And if you’re ready for more support, I’ve got options—whether it’s my brand-new ebook⁠⁠⁠ ⁠Fuel Smarter, Run Stronger⁠⁠⁠⁠, my group program⁠⁠⁠ ⁠The Fuel Train Recover Club,⁠⁠⁠⁠ or apply for personalized⁠⁠⁠ ⁠1:1 coaching ⁠⁠⁠⁠this season.