You're Probably Drinking Water Wrong. And Yes, You Can Drink Too Much.

The Thing Nobody Talks About — Yes, You Can Drink Too Much

Most people understand dehydration. Lose too much fluid, your heart works harder, your temperature rises faster, performance drops, fatigue arrives sooner.

But the less discussed problem is the other direction.

Drinking too much plain water — especially during long or sweaty sessions — can dilute the sodium in your blood. This is called hyponatraemia: low sodium levels from excessive fluid intake.

It's not just a marathon runner problem. Anyone exercising at a low to moderate intensity for an extended period while forcing down large amounts of plain water can be at risk.

So the goal is not to drink as much as possible. The goal is to replace what you need, when you need it.

Phase 1 — Before Training

Last-minute chugging is not a strategy.

If you drink a large bottle of water five minutes before you train, most of it sits in your stomach, makes you uncomfortable, or sends you to the toilet before you've lifted anything.

The guidance from the American College of Sports Medicine is to drink 5 to 7 millilitres per kilogram of body weight approximately four hours before exercise. For a 70kg person, that's roughly 350 to 490 millilitres.

That timing matters because it gives your body time to absorb the fluid properly, distribute it, and clear any excess before you start.

A simple check before you train: if your urine is very dark, or you've barely urinated in the last few hours, you probably haven't been drinking enough through the day.

The solution is not to panic and chug water immediately before training. It's to drink steadily through the hours leading up to it.

Phase 2 — During Training

The main goal while you're exercising is straightforward: don't lose more than 2% of your body weight in fluid.

That sounds precise, but in practice it means this — pay attention to how you feel, and don't ignore thirst.

For most normal gym sessions, plain water is perfectly adequate. A regular strength training workout under an hour, at moderate intensity, in a reasonably cool environment — water is fine, and drinking to thirst is a reasonable approach.

When water alone may not be enough: If you're training hard for more than an hour, sweating heavily, working in heat or humidity, or doing longer endurance-style sessions — plain water is often not the best tool on its own.

In those situations, your fluid needs include:

• Sodium — to replace what's lost in sweat
• Some potassium — for the same reason
• 5 to 10% carbohydrate — to support blood glucose and delay fatigue

That combination improves fluid absorption, replaces what's actually being lost, and helps you sustain output longer.

What About Sports Drinks?

Not every session needs one. But long, hot, sweaty sessions are a different story.

A decent sports drink doesn't do anything magical. It does three practical things: replaces some sodium, provides some carbohydrate for fuel, and helps your body hold onto fluid better than plain water alone during prolonged exercise.

If your session is 45 minutes of strength training in a normal gym — you don't need one.

If you're running in the heat for 90 minutes, or doing a long training session with significant sweat — it can genuinely help.

The Sloshing and Cramping Myth

A lot of people avoid drinking during exercise because they're worried about stomach discomfort.

Usually the real issue isn't hydration itself. It's how much, how fast, or what kind of drink. Very sugary drinks, very large amounts consumed quickly, dehydration, and high-intensity effort can all contribute to gut problems.

Steady hydration with the right fluid, consumed in manageable amounts, is a completely different experience. The answer isn't "don't drink." The answer is "use the right amount and the right type."

Phase 3 — After Training

If you finish a hard session noticeably lighter than when you started, you haven't magically lost body fat in an hour. You've mostly lost water. And that needs to go back.

If recovery needs to happen quickly — you're training again soon, or it was a very hard session — the target is 1.5 litres of fluid for every kilogram of body weight lost.

That's more than a simple one-for-one replacement, because your body will lose some of that fluid in urine as it rebalances. The extra accounts for that.

Why Sodium Matters More Than People Think

Here's where most people get post-training hydration wrong.

They finish training, drink a lot of plain water, and assume the job is done.

But recovery hydration isn't just about replacing fluid. It's about holding onto that fluid.

Sodium helps your body retain the fluid you're drinking. Without it, you can drink significant amounts of water and still not rehydrate effectively.

Sodium stimulates thirst. It replaces what was lost in sweat. Without it, you can drink significant amounts of water and still not rehydrate effectively — because you'll just excrete it.

This is why your post-training meal matters for hydration, not just for protein and carbohydrates. The sodium in a normal meal does real work.

Sometimes the best recovery drink isn't another giant bottle of plain water. It's water, a normal meal, and the sodium that comes with real food.

The Simple Version

The Bottom Line

Your body doesn't need constant flooding. And it doesn't need to be starved of fluid either.

It needs the right amount at the right time.

Drink too little and performance drops. Drink too much plain water and you create a different problem entirely.

Hydration is not about extremes. It never has been. It's about balance, timing, and context.

Give your body what it actually needs. Exactly when it needs it.