For my husband and I, our 2025 New Year’s resolution was ambitious but simple: get fit, stay fit and do it together. That meant a joint gym membership—just for the grown-ups—and a mutual promise to trade takeout for treadmills. Signing up was the easy part. Actually showing up every week? That’s where things got slippery.
Naturally, our new fit version of ourselves needed a wardrobe makeover: matching activewear, shiny new runners, pastel yoga mats, sleek water bottles and colour-coordinated towels. Instagram-ready? Absolutely. Sustainable motivation? Not so much.
Once the novelty wore off and the reality of early alarms, sore muscles and sweat puddles set in, our focus shifted to a new obsession: hydration.
the beverage renaissance
Post-gym, our kitchen became a battleground for beverages. My husband led the anti-water revolution, stockpiling everything from Diet Coke and iced teas to craft kombuchas. According to him, water was “flavourless, boring and insufficient” after a good sweat.
I, on the other hand, was team H2O. A dentist by trade and by temperament, anything sugary or acidic sets off my professional alarm bells. To me, these drinks were not hydrating—they were dental sabotage in a bottle. Honestly, if dental boards saw the pH levels in our fridge, I would have had my licence revoked on the spot. And so, the “Great Beverage War” began.
At first, I tried diplomacy. I quietly relocated his fizzy recruits to the laundry cupboard—out of sight, out of mouth. But soon, tensions escalated into full-blown debates, complete with scientific references hurled across the kitchen. My husband, donning his “medical critical thinking” cap, demanded evidence-based proof that water is the superior post-gym rehydration option. Challenge accepted. I plunged headfirst into the research, thirstier for vindication than for hydration. There were scientific studies quoted at the dinner table and physiological facts texted mid-workday. It became the docudrama titled Hydrology: Domestic Edition.
Below are a few key findings—so you, dear reader, can decide for yourself who is wrong and who is (as always) right.
water: the unsung hero
Let’s start with the basics: water is essential. Our need for it surpasses what our bodies can produce, and without it, we wouldn’t survive more than three days.1
Our bodies are made up of 50 to 80 per cent water, depending on age, gender and body composition. Men usually have a higher water percentage thanks to their greater muscle mass. As we age, our internal water content dwindles.2,3 On average, we lose two-and-a-half to three litres of water per day just by existing—breathing, sweating, going to the toilet. That’s before exercise.4
On average, we lose two to three litres of water per day by breathing, sweating, going to the toilet.
Water isn’t just filling space. It’s crucial for digesting food, transporting nutrients, defending the immune system, regulating temperature and getting rid of waste.2 Despite what Instagram wellness trends suggest, there’s no one-size-fits-all rule. The classic “eight glasses a day” is more of a helpful myth than a strict science.4
what is hydration, really?
Hydration isn’t just about guzzling fluids. It’s about keeping a balance of water and electrolytes—charged minerals like sodium, potassium, chloride, magnesium, etc. These keep our muscles moving, nerves firing and cells from going haywire.5,6 But hydration isn’t just about what you sip. About 20 per cent of our daily fluids come from food. Fruits like watermelon, strawberries, and rock melon are practically edible water. Veggies like cucumber, lettuce and celery are hydration heroes. 1,7
sweat science
Sweating throws that balance off. Sweat is your body’s way of staying cool. It’s 99 per cent water and one per cent minerals and fat. How much you sweat depends on your workout, your biology and even your mood.8 Even a one-to-two per cent drop in body weight from fluid loss can cloud your thinking, slow your reaction time and mess with your mood. That’s not ideal when you’re trying to out-lunge the guy next to you in the weights room. So, drink up before making any life-altering decisions—or lifting heavy weights.9 That’s where rehydration comes in.
can you drink too much?
Yes, surprisingly. Overhydration, though rare, can dilute your blood’s sodium levels and cause cells to swell. This condition—hyponatraemia—can be dangerous, even fatal. So yes, there is such a thing as too much of a good thing.10,11
Dehydration shows up in sneaky ways:
Want a quick check? Examine your first morning bathroom trip. If your urine is the colour of weak lemonade, congrats—you’re hydrated. If it’s more like strong coffee, it’s time to top up.9,13 Vulnerable groups—babies, children, pregnant women and older adults—require extra hydration care.2,4,8
so, what should you drink?
Let’s break it down:
Mild dehydration: Water is king. It replenishes fluids, neutralises acids, washes away bacteria and keeps your mouth happily moist. Bonus: tap water contains fluoride, which helps prevent cavities.1,14,15
Moderate dehydration: Oral rehydration solutions (ORS) come to the rescue. These contain a precise balance of salt, sugar and minerals—great for post-gym, travel or if you’ve lost too much water too quickly (such as when you’re sick).
Severe dehydration: Don’t mess around—this needs IV fluids and a trip to the Emergency Department.
But hydration isn’t just about what you sip. About 20 per cent of our daily fluids comes from food. Fruits like watermelon, strawberries and rockmelon are practically edible water. Veggies like cucumber, lettuce and celery are hydration heroes.1,7
drinks vs teeth
This is where the plot thickens—especially if you, like me, care about enamel. A dentist’s most loyal liquid ally? Plain old water—it’s like the Swiss Army knife of drinks, just less flashy and way better for your enamel.
Many “hydrating” drinks are a liquid evil in a cavity-inducing disguise:
- Sports drinks: high sugar content equals tooth decay
- Alcohol: diuretic and acidic
- Coffee/tea/sodas: often acidic and may contain hidden sugars
Better bets:
- Milk (dairy or plant-based)
- Coconut water
- Oral rehydration solutions
These may even hydrate better than water. But proceed with caution—they’re not exactly cavity neutral.9,11
hydration tips
Want to stay hydrated without overthinking it?
- Sip water regularly throughout the day
- Flavour your water with fruit or mint
- Eat more water-rich fruits and veg
- Use a hydration tracker or app
- Check your urine colour
- Drink before, during and after exercise
You don’t need to tote a gallon jug everywhere. Just listen to your body—and maybe your dentist.11,12
So, after an exhaustive dive into fluid science, what’s the takeaway? I admit—albeit begrudgingly—that my husband isn’t entirely wrong. Some drinks might technically rehydrate better than water. But most come with baggage, especially for your teeth. In our house, we’ve reached a diplomatic hydration pact. The top shelf of the fridge is reserved for water, coconut water and ORS sachets. Everything else must now submit a formal application to the Australian Dental Association before it can earn fridge real estate.
So, don’t be afraid to thirst—but do it wisely, my friends.
hydration hack
Add sliced cucumber and mint to your water for a flavour boost that won’t harm your teeth—or your relationship.
- healthline.com/health/food-nutrition/how-long-can-you-live-without-water?utm_source=ReadNext#bodily-response ↩︎
- eatforhealth.gov.au/nutrient-reference-values/nutrients/water ↩︎
- healthdirect.gov.au/drinking-water-and-your-health#why ↩︎
- theconversation.com/dont-like-drinking-plain-water-10-healthy-ideas-for-staying-hydrated-this-summer-191859 ↩︎
- medlineplus.gov/fluidandelectrolytebalance.html ↩︎
- medicalnewstoday.com/articles/153188 ↩︎
- healthbenefitstimes.com/health-wiki/hydration/ ↩︎
- scienceabc.com/humans/people-sweat-more-than-others-men-women-perspiration-sweat-glands-exercise.html ↩︎
- theconversation.com/why-do-i-wake-up-thirsty-183731 ↩︎
- healthline.com/health/overhydration#causes ↩︎
- athleticinsight.com/sports-terminologies/hydration ↩︎
- healthline.com/health/dehydration#symptoms ↩︎
- theconversation.com/health-check-whats-the-deal-with-electrolytes-31729 ↩︎
- dentalhealth.org/the-role-of-hydration-in-oral-health ↩︎
- nhmrc.gov.au/health-advice/public-health/fluoridation ↩︎
