Episode 214 - Sweat Science: The Truth About Electrolytes and Hydration for Triathletes

Sweat Science: The Truth About Electrolytes and Hydration for Triathletes

Electrolyte drinks are everywhere – from pastel powders to wellness patches and Insta-worthy bottles. But are they helping your performance, or just making expensive pee?

In this episode, I unpack the truth behind the electrolyte hype. You’ll learn when electrolytes actually matter, how to spot a rubbish product, and the real risks of getting hydration wrong. Whether you're a salty sweater, training in the heat, or prepping for long-course racing, this one’s essential listening.

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Episode Transcription

Episode 214: Sweat Science: The Truth About Electrolytes and Hydration for Triathletes

Welcome to the Triathlon Nutrition Academy podcast. The show designed to serve you up evidence-based sports nutrition advice from the experts. Hi, I'm your host Taryn, Accredited Practicing Dietitian, Advanced Sports Dietitian and founder of Dietitian Approved. Listen as I break down the latest evidence to give you practical, easy-to-digest strategies to train hard, recover faster and perform at your best. You have so much potential, and I want to help you unlock that with the power of nutrition. Let's get into it.

Taryn Richardson (00:00)
Everywhere you look right now, someone’s sipping on a pastel-coloured electrolyte drink thinking it’s their secret to eternal youth.

We’ve got skin patches, chews, powders, coconut water in disguise. We’ve well and truly hit the peak of this electrolyte trend. Social media would have you believe that plain water is dangerous, and unless you’re adding a sachet of something coloured and salty to everything you drink, you’re missing out on some sort of hydration edge.

And look, I get it. Electrolytes sound sexy and sciencey. The marketing is so slick, especially the stuff targeted to women. It’s sexy, sparkly, and selling hard. But just because something says it’s an electrolyte drink doesn’t mean it’s doing what you think it’s doing.

I was interviewed for the Australian Financial Review on exactly this — the rise of electrolyte drinks in the general population where people think they’re missing a competitive edge by not using them. So today, I want to expand on that, cut through the hype, and get into the actual science of when, why, and how to use electrolyte drinks properly from an endurance-athlete perspective — not as someone sipping their hydration beverage on the way to Pilates.

We’ll unpack how unique your hydration needs are, the dangers of over-hydrating, when electrolytes really matter, and how to pick a product that’s right for you.

Electrolyte drinks are everywhere: powders, pills, tablets, capsules, chews — even skin patches promising to deliver magic minerals straight through your arm. Social media would have you believe that if you’re not sipping one daily, you’re missing out on a wellness miracle.

Unless you’re training for long periods, potentially in heat and humidity, and sweating bucket-loads, you’re probably just making expensive pee.

Electrolytes are marketed to help you rehydrate faster and boost energy, especially for women. They come in pretty pastel bottles and sachets that look like candy and make you feel like you’re doing something good for your health. But let’s be clear — just because it’s labelled as an electrolyte drink doesn’t mean it’s necessary or useful.

For us as triathletes, we do need to understand electrolytes because we’re training long and hard, usually in conditions where sweat loss actually matters.

The most important electrolyte we lose in sweat is sodium. We also lose small amounts of potassium, magnesium, and calcium, but sodium is the big one — the main one to focus on. Your sodium loss varies widely between individuals, which is why your electrolyte needs are unique.

Marketing BS aside, as athletes we need to make smarter decisions based on science, not TikTok trends or what the lady in the health-food shop told you.

Your electrolyte needs depend on your sweat rate and your sweat sodium concentration — both unique to you. I’ve seen triathletes lose as little as 200 milligrams of sodium per litre of sweat and others over 2000. That’s a tenfold difference, which is why generic advice from the internet won’t cut it.

Sweat rate is influenced by genetics, training status, fitness level, body size, and environment. Training outdoors at 35°C is vastly different to riding indoors in winter.

Some athletes finish sessions covered in salty crusts, while others barely sweat. Most don’t actually know what they’re losing. Inside the Triathlon Nutrition Academy program, I teach athletes how to calculate sweat rate, measure sweat sodium concentration, and most importantly, apply that data practically to training and racing.

It’s not a one-off test. You need to repeat it over time to understand your own pattern. That’s how you get lasting results.

One of my athletes, Chris — let’s call him the Human Sprinkler — kept DNFing races. He thought it was a fueling problem. He knew he was a heavy sweater but had no idea how much. Once we tested, we discovered he was a very salty margarita, and we fixed his plan. Now he races without issues.

The lesson? Sweat is more than just water. Your needs are unique. You must test and understand them.

Now, before we get practical, let’s talk about hyponatremia — when your body’s sodium levels drop too low. In endurance sports, it usually comes from over-drinking plain water or not replacing sodium. It sounds harmless, but it’s not. It can be life-threatening. You might feel nauseous, bloated, or foggy and think you’re dehydrated, so you drink more — making it worse. Severe cases lead to confusion, vomiting, seizures, or collapse.

That’s why “drink to thirst” doesn’t always hold up. You can overdo it just as easily as under-do it. The goal is to find your personal sweet spot.

So, when should you use electrolytes? If you’re training longer than about four hours, it’s hot, or you’re a heavy or salty sweater, electrolytes matter.

A 2025 review paper on fluid and sodium balance found many athletes’ issues — cramping, gut upset, hyponatremia — stem from a mismatch between what they lose and what they replace.

If you’re smashing litres of plain water without sodium, you’re setting yourself up for disaster. But you don’t need to replace sodium daily — food gives you plenty. In fact, two slices of bread contain more sodium than a bottle of Gatorade.

Electrolytes help during long sessions, hot conditions, and races like 70.3 or full-distance triathlons. Outside of that, water is fine — as long as you eat real food. Electrolytes are a tool, not a magic fix.

So, how do you choose the right electrolyte product? There are powders, tablets, capsules, drinks, dissolvable strips, even salt licks. Whatever you pick, remember: not all are created equal.

Check the sodium content first. That’s the main player. If it barely has any sodium, it’s not worth your time. Next, look at sugar or carbs — depending on whether you’re using it for fueling or just hydration.

Delivery format matters too. Some prefer all-in-one sports drinks; others like capsules or tablets. Find what works for you and your gut.

Avoid “fairy-dust” products — the ones that list every mineral under the sun in tiny, useless amounts. They look impressive on a label but do nothing in reality.

Finally, pick something you like the taste of. If it’s too salty or artificial, you won’t drink enough.

So, quick recap — check sodium content, check carbs, pick a delivery format that suits your training, avoid fairy dust, and make sure it’s palatable.

That’s your crash course in choosing electrolytes. Don’t fall for shiny packaging or fluffy claims. Choose what matches your sweat needs, your race conditions, and your body.

If you want help building a personalised hydration strategy based on your data, that’s exactly what I teach inside the Triathlon Nutrition Academy.

Electrolyte drinks aren’t bad, but they’re not magic either. You need to understand when, how much, and which ones to use — based on your sweat rate, sodium concentration, and conditions.

So, if you’re serious about getting your hydration right, join the Triathlon Nutrition Academy program. We’ll go beyond the basics and build a hydration plan that fits your race goals perfectly.

If you’re ready to stop guessing and start getting results, head to dietitianapproved.com/academy and register your interest in the next intake.

Until next time — skip the fairy dust. Use your brain. You’re an intelligent human. Hydrate smart, and use electrolytes strategically. See you next week.

Thanks for joining me for this episode of the Triathlon Nutrition Academy podcast. I would love to hear from you. If you have any questions or want to share with me what you've learned, email me at [email protected]. You can also spread the word by leaving me a review and taking a screenshot of you listening to the show. Don't forget to tag me on social media, @dietitian.approved, so I can give you a shout out, too. If you want to learn more about what we do, head to dietitianapproved.com. And if you want to learn more about the Triathlon Nutrition Academy program, head to dietitianapproved.com/academy. Thanks for joining me and I look forward to helping you smashed in the fourth leg - nutrition!