We all think we’re doing the right things — drinking plenty, training smart, and staying on top of nutrition.
But sometimes, what feels right isn’t actually helping performance.
Recently I have been noticing (on social media, in races, even on the sidelines) athletes are sipping brightly coloured drinks, convinced that more liquid means better hydration.
The message is everywhere: drink more and you’ll perform better.
But the science tells a different story.
Did you know that nearly 60 % of endurance athletes either over-hydrate or under-replace sodium during hot conditions? Both mistakes reduce endurance and increase fatigue.
Hydration for triathletes and cyclists isn’t about how much you drink or how colourful it looks.
It’s about understanding why, when, and what your body truly needs.
In this article, we’ll unpack the science behind sweat and salt, explain why sodium matters more than marketing, and show you how to build a hydration strategy that fits you — not the latest trend.
Because hydration isn’t about what’s in your bottle; it’s about knowing your body, your conditions, and your purpose.
Hydration hype vs. hydration reality
Electrolytes are minerals — mainly sodium, potassium, magnesium, and calcium — that regulate fluid balance, muscle contraction, and nerve signals.
The key player for endurance athletes is sodium, because it’s the one we lose most in sweat.
Research shows sodium losses can vary widely — from 200 mg to over 2000 mg per litre — depending on genetics, environment, and training history (Sawka et al., 2007).
That means your sweat composition is as individual as your fingerprint.
When it’s hot, humid, or you’re deep into race prep for events like Honeysuckle Hammer or Challenge Canberra, your sweat rate spikes — and hydration errors are amplified.
If you missed my earlier summer training guide, you can read it here — Summer Training Essentials: Stay Safe, Hydrated, and Protected. It’s a great overview of staying safe in the heat before applying this deeper hydration strategy.
When electrolytes actually matter
✅ Use electrolyte drinks when:
- Sessions last longer than 90 minutes, especially in heat or humidity
- You notice salt streaks on your kit or skin
- You’re a heavy or “salty” sweater
- You cramp or feel dizzy late in sessions
🚫 Skip them when:
- Sessions are short or cool
- You’re hydrating day-to-day — food provides enough sodium
Over-hydrating with plain water can lead to hyponatremia, when blood sodium drops too low.
It’s more common than many realise and can cause nausea, bloating, confusion, and, in extreme cases, collapse (Hew-Butler et al., 2020).
The goal isn’t more hydration; it’s balanced hydration — replacing what you lose.
Why more salt isn’t always better
The supplement industry loves to sell the idea that “more” equals “better.”
But too much sodium can upset your stomach and slow absorption.
Think of your gut as a finely tuned engine, not a salt shaker — it performs best when chemistry stays balanced.
A 2025 review found that most athlete hydration issues — cramping, gut problems, and fatigue — came from a mismatch between sodium lost and sodium replaced, not simply lack of electrolytes (Smith et al., 2025).
Quick checks:
- Aim for 400–800 mg sodium per 500 ml bottle during long, hot sessions.
- Skip “fairy-dust” blends listing 20 minerals in trace amounts.
- Choose a flavour you enjoy — if it tastes awful, you won’t drink enough.
Remember: electrolytes support hydration; they don’t replace real food.
Hydration is personal — my why
When I first started racing, I thought drinking more was the key, especially on those hot days..
I finished events feeling bloated, heavy, and blah — convinced I was doing everything right.
It wasn’t until I tracked sweat rate and conditions that I realised how different every session was.
A long summer ride in Canberra heat felt nothing like a a humid ride or cool indoor trainer session.
That’s when I learned that hydration for triathletes and cyclists isn’t one-size-fits-all.
Now, when I coach riders and triathletes, we focus on awareness before volume.
Once you understand how your body responds, you can make confident, informed choices — not emotional ones.
How to find your hydration sweet spot
1: Measure your sweat rate
Weigh yourself before and after a session (without clothes).
Subtract what you drank; every 1 kg lost ≈ 1 L of sweat.
2: Estimate sodium loss
Notice salt marks on your kit or skin — that’s visible data.
3: Match your drink to your session
Hot, long, or intense sessions = electrolyte drink.
Short or easy = water is fine.
4: Train the gut
Practise with your hydration plan in training, not on race day.
5: Keep it simple
Your everyday meals usually replace enough sodium. Don’t chase numbers; chase consistency.
The bigger picture
Hydration rarely limits performance — until it does.
When it goes wrong, the drop-off is fast.
The best athletes don’t hydrate more; they hydrate smarter.
They test, adjust, and learn what their bodies need so they can trust the process on race day.
If you can do that, you’re not just surviving summer sessions — you’re performing with purpose.
Ready to personalise your hydration?
If you’re unsure what your sweat and salt story looks like, let’s map it out together.
Book a free strategy call, and we’ll build your personalised hydration plan so you can stop guessing — and start racing with confidence.
References
- Sawka MN et al., 2007. ACSM Position Stand: Exercise and Fluid Replacement. Med Sci Sports Exerc. 39(2): 377–390.
- Hew-Butler T et al., 2020. 3rd International Exercise-Associated Hyponatremia Consensus. Clin J Sport Med.30(4): 319–325.
- Smith CJ et al., 2025. Fluid and Sodium Balance in Endurance Athletes: A Review. Sports Med. 55(2): 145–162.
- Triathlon Nutrition Academy Podcast Ep 214 — Sweat Science: The Truth About Electrolytes and Hydration for Triathletes.