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Science

The research underneath the marketing. What sweat actually contains, how thirst really works, and what the literature does and doesn't support about hydration.

A lot of the marketing in this category gets ahead of the research. These articles look at what the published literature actually says - about sweat composition, exercise-associated hyponatremia, cognitive effects of mild dehydration, and the underlying physiology of how the body manages fluid balance. We try to be honest about what's known, what's uncertain, and what's hype.

Brands featured across our coverage: BSc Body Science · Bulk Nutrients · Dr.Hydrate · Endura · Gatorade · High5 · Hydralyte · Liquid I.V. · LMNT · LVL UP · Maurten · Musashi · Nuun · Pedialyte · Powerade · Precision Fuel & Hydration · SiS - Science in Sport · Skratch Labs · Sodii · Staminade · Switch Nutrition · Tailwind Nutrition · True Protein.

Key Takeaways

Sweat composition varies enormously between individuals - 7-fold for sodium concentration.
Heat acclimatisation adapts sweat rate and composition over 7-14 days of repeated exposure.
Exercise-associated hyponatremia is a real but uncommon endurance-event risk; modern guidance is to drink to thirst with sodium-containing drinks.
Mild dehydration measurably affects cognitive performance - not transformative, but real.
ACSM guidance is the standard reference for sport hydration in published research.

How to Read Hydration Research

A lot of hydration content gets ahead of the research. A few useful heuristics:

Distinguish published research from marketing. Sports nutrition is one of the most-studied fields in exercise science, and bodies like the American College of Sports Medicine (ACSM) and NHMRC publish summary guidance. Brand claims that go beyond those are marketing.
Individual variation matters. Sweat rate and sweat sodium vary up to 7-fold between people. What's right for someone else may not be right for you.
The body's signals are useful. Thirst, urine colour, perceived effort, and morning energy all give honest feedback that no lab test fully replaces.

This category covers the underlying physiology in plain language.

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Science

How the Body Sheds Heat

Sweating is only one of four ways the body loses heat, and in an Australian summer most of the others stop helping.

June 25, 2026 6 min read

Science

Urine Colour Charts: How Useful Are They?

The colour chart on the gym wall is the most widely used hydration check there is. What it can tell you, and what throws it off.

June 20, 2026 5 min read

Science

Sweat Testing: What It Measures and Who It's For

Sweat sodium testing is increasingly offered to recreational athletes. What the test measures, what it doesn't, and when it is worth doing.

June 15, 2026 6 min read

Science

Osmolality Explained: What That Number Means

Osmolality sits behind the isotonic and hypotonic labels on sports drinks. A plain-English explanation of what it measures.

June 11, 2026 6 min read

Science

Cramps and Hydration: What the Evidence Says

Cramp is often blamed on dehydration or low electrolytes. A look at what the research actually supports, and what it doesn't.

June 6, 2026 6 min read

Science

The Science of Sweat: What You're Actually Losing

Sweat is more than salty water. A look at what the research says about sweat composition, individual variation, and the implications for replacing what you lose.

May 31, 2026 8 min read

Science

Hyponatremia in Endurance Athletes: An Honest Look

Drinking too much water during long endurance events causes a documented condition: exercise-associated hyponatremia. Here's the picture, without sensationalism.

May 25, 2026 8 min read

Science

Why You Can Feel Thirsty When You're Not Dehydrated

Thirst is a complex signal. It's tied to mouth dryness, blood sodium, hormones, and habit - which is why the cue and the actual fluid status don't always line up.

May 20, 2026 6 min read

Science

The 60 Percent Number: How Much of You Is Water

"The human body is 60% water" is a familiar statistic. A closer look at what that number actually means, and how it changes through life.

May 15, 2026 6 min read

Science

Hydration and Cognitive Performance: What Research Shows

Even mild dehydration measurably affects attention, mood, and short-term memory. A look at the research and what it implies for working days.

May 9, 2026 7 min read

Science

Chloride: The Forgotten Electrolyte

Chloride lives in the shadow of sodium and potassium, but it's the second-most concentrated mineral in your sweat. A short look.

May 4, 2026 5 min read

Science

Bicarbonate and Why Some Drinks Include It

A handful of sports drinks include bicarbonate or citrate. A short look at why, and the research on its effects.

April 30, 2026 5 min read

Science

The Sodium-Glucose Pump

Why sports drinks include both sodium and a small amount of carbohydrate - a brief tour of the absorption mechanism that underpins oral rehydration.

April 25, 2026 6 min read

Science

The 1-Hour Rule: Where Did It Come From?

"Sports drinks only matter after an hour of exercise" is widely repeated. A look at the rule's origin and current status.

April 21, 2026 5 min read

Science

Why Some People Sweat More Than Others

Sweat rate varies enormously between individuals. A look at what drives the variation - and why it matters for hydration choice.

April 17, 2026 6 min read

Science

Heat Acclimatisation: What Actually Adapts

Spend a fortnight training in heat and your body changes. A practical look at what adapts and how to leverage it.

April 13, 2026 6 min read

Frequently Asked

Why do some people sweat more than others?

Body size, fitness level, heat acclimatisation, hydration status, and genetics all contribute. Why some people sweat more walks through each variable.

Is hyponatremia a real risk?

Yes - exercise-associated hyponatremia is documented in endurance research, particularly among slower marathoners and ultramarathon participants. Most cases are mild; severe cases are uncommon but serious. Modern guidance avoids over-drinking and favours sodium-containing drinks during long events.

Can hydration improve my mental performance?

Adequate hydration supports normal cognitive function. Mild dehydration measurably affects attention, mood, and short-term memory in research studies. Going above adequate doesn't deliver further cognitive benefit - the curve is flat above adequate intake.

Does the body 'detox' through sweat?

Not in any meaningful sense. The body uses urine and stool for waste excretion, not sweat. Sweat is a temperature-regulation mechanism with small amounts of minerals dissolved in mostly water.

Science

How to Read Hydration Research

All Articles in Science

How the Body Sheds Heat

Urine Colour Charts: How Useful Are They?

Sweat Testing: What It Measures and Who It's For

Osmolality Explained: What That Number Means

Cramps and Hydration: What the Evidence Says

The Science of Sweat: What You're Actually Losing

Hyponatremia in Endurance Athletes: An Honest Look

Why You Can Feel Thirsty When You're Not Dehydrated

The 60 Percent Number: How Much of You Is Water

Hydration and Cognitive Performance: What Research Shows

Chloride: The Forgotten Electrolyte

Bicarbonate and Why Some Drinks Include It

The Sodium-Glucose Pump

The 1-Hour Rule: Where Did It Come From?

Why Some People Sweat More Than Others

Heat Acclimatisation: What Actually Adapts

Frequently Asked

Stay Ahead of Your Hydration.