Why We Did Sodium Differently

Everyone's adding more. We added exactly the right amount. Here's the science that made us rethink the electrolyte category and why getting hydration wrong on race day costs you more than you think.

If you've spent any time in the endurance world or been marketed to by electrolyte drinks, you've probably seen the arms race. More sodium. Higher doses. Bigger numbers on the label. The marketing logic goes: sweat is salty, so more salt means better hydration. But when we sat down with Dr. Dan Plews, our Head of Research, to formulate Electrolyte Hydration, we started from a completely different question.

Not how much sodium can we fit in a serve? But, what does the science actually say.

What Sweat Actually Takes From You

When you sweat, you lose a mix of electrolytes, but sodium is by far the dominant one. On average, you lose somewhere between 460–920mg of sodium per litre of sweat, with the full observed range sitting between 200–2,000mg/L depending on conditions, how heat-acclimatised you are, and what your diet looks like day to day.

Here's something that surprises most people: sweat sodium variation is not primarily genetic. It reflects your training history and your sodium intake. The more you train and the more dialled in your nutrition, the more efficient your body becomes at managing electrolyte loss.

Beyond sodium, your sweat also carries potassium, critical for membrane potential and cellular rehydration and magnesium, which plays a role in enzyme function, muscle contraction, and ATP synthesis. That's why a complete electrolyte profile matters.

The Word Nobody Talks About: Osmolarity

This is where most electrolyte products quietly get it wrong and where we think the conversation in the industry needs to evolve.

Osmolarity is the concentration of dissolved particles in a solution. For a drink to be absorbed quickly and effectively, that concentration matters enormously:

• Hypotonic (<270 mOsm/kg)  absorbed faster than blood plasma. Ideal as a standalone hydration drink.

• Isotonic (270–330 mOsm/kg)  matches blood plasma concentration. Absorbed well.

• Hypertonic (>330 mOsm/kg) reverses the osmotic gradient. Instead of fluid moving into your body, water moves OUT of your bloodstream and INTO your gut, causing bloating, nausea, and delayed absorption.

At the recommended serve of 7g per 500ml, PILLAR Electrolyte Hydration delivers approximately 100–130 mOsm/kg, well hypotonic and rapidly absorbed, even before a single gram of carbohydrate hits the mix.

Why This Matters On Race Day

Here's the problem with high-sodium products that most brands aren't talking about: on race day, you're not drinking plain water. You're taking gels. You're running on carbohydrates. And every gram of carbohydrate in your system changes the osmolarity of what you're consuming.

We modelled exactly what happens when you pair different electrolyte doses with real-world race nutrition:

The table tells the real story. A high-sodium product paired with a standard race gel crosses into hypertonic territory, the exact situation that causes the GI distress athletes blame on their gels, their food, or just "a bad day." In reality, it's often the interaction between sodium load and carbohydrate that tips the balance.

Research note: Dr. Dan Plews, Head of Research: There is no scenario where 1,000mg Na per 500ml outperforms 400mg. In every scenario involving carbohydrates, excess sodium actively harms gut function, fluid delivery, and performance. The ACSM sports drink recommendation sits at 500–700mg/L - a 1,000mg/500ml product is 2.8–4x that guidance.

The GI Issue Nobody Wants to Admit

GI distress is the number one reason athletes abandon their race nutrition plan. Studies show 30–50% of Ironman athletes report significant GI symptoms during racing — nausea, bloating, vomiting, diarrhoea, abdominal cramping. Most write it off as gut sensitivity or nerves. Often, it's osmolarity.

The key modifiable risk factors aren't mysterious. High-osmolality drinks and gels. High fructose intake. Solid food during high-intensity efforts. Dehydration. Every one of these is addressable, and osmolarity-aware product formulation is where it starts.

PILLAR Electrolyte Hydration is designed to stay within the hypotonic to isotonic window across real-world race scenarios. Not just in a lab setting with plain water, but when you're actually racing and fuelling with gels, pushing hard, and asking a lot of your gut.

The Full Profile: Sodium, Potassium, Magnesium

We landed on our electrolyte ratios for specific, evidence-based reasons:

• 400mg Sodium: the evidence-based target for optimal hydration. Hypotonic standalone, rarely hypertonic in real-world use, and aligned with ACSM guidance. Not 600mg, not 1,000mg. 400mg.

• 190mg Potassium: supports membrane potential and cellular rehydration post-exercise. The citrate form also buffers acidity, which matters in high-intensity efforts.

• 80mg Magnesium (25% RDI): covers sweat losses and functions as an ATP synthesis cofactor. Delivered in citrate form for absorption efficiency.

No added sugar. No artificial flavours. Informed Sport Certified across every batch, so athletes competing under anti-doping regulations know exactly what they're putting in their body.

What We're Changing

The electrolyte category has defaulted to "more is more" with increased competition. Yes, more sodium looks impressive on a label and is easy to market. 

We built Electrolyte Hydration around one principle: formulate for what the body can actually absorb, not what looks good on a nutrition panel. That means understanding osmolarity. Understanding how electrolytes interact with carbohydrates. And being willing to use a number like 400mg sodium when everyone else is chasing 1,000mg.

That's the White Line Range difference. Not louder, just smarter.

This post is intended for general education. Always consult a healthcare professional before commencing supplementation.