How to Hydrate Properly During a Long Workday

Most hydration advice is aimed at athlètes. But for the millions of people spending 8-10 hours a day at a desk, in meetings, or commuting, hydration at work is just as important , and far more neglected. Research consistently shows that even mild dehydration impairs cognitive performance, reduces mood, and increases feelings of fatigue. If you're trying to do your best thinking at work, what you drink matters.

Why Office Workers Are Chronically Underhydrated

Several factors combine to make dehydration particularly common in office environments. Air conditioning removes moisture from the air, increasing insensible water loss through breathing. High cognitive load increases metabolic demand. Coffee and tea , the default office drinks , have mild diuretic effects that increase fluid loss. And unlike physical exercise, desk work provides no obvious cue to drink.

The result is that many knowledge workers are mildly dehydrated for much of their working day without realising it.

The Cognitive Cost of Dehydration

Studies have shown that a fluid deficit of just 1-2% of body weight , roughly 700ml to 1.4 litres for an average adult , is enough to impair working memory, concentration, reaction time, and mathematical ability. Mood and perceived energy levels are affected at similar thresholds.

For someone whose job requires sustained analytical thinking, writing, communication, or decision-making, this is a meaningful performance cost that can be addressed simply by drinking the right things consistently.

A Practical Hydration Strategy for the Workday

Start with electrolytes, not coffee

Before your first coffee of the day, have an electrolyte drink. After 7-8 hours of sleep without drinking, your electrolyte levels are depleted. Rehydrating with sodium and potassium first thing gives your brain and body a genuine start to the day.

Keep a drink visible at your desk

Out of sight, out of mind. If you have to get up and go to the kitchen every time you want a drink, you'll drink less. Keeping a bottle or can at your desk is one of the simplest behaviour changes you can make to increase daily fluid intake.

Anchor hydration to existing habits

Connect drinking to things you already do regularly: have a drink when you sit down at your desk, when you open your laptop, before each meeting, or after each bathroom break. Habit stacking makes hydration automatic rather than effortful.

Recognise the mid-afternoon dip as a hydration signal

The 2-3pm energy slump many people experience is partly circadian and partly dehydration. Before reaching for a second or third coffee, try an electrolyte drink. In many cases, the fatigue resolves within 20-30 minutes.

What to Drink

Water is the foundation, but electrolytes are what make hydration effective. For a long workday, a good approach is 2-3 litres of plain water spread through the day, supplemented by one électrolyte drink , ideally at the start of the day or when the afternoon dip hits.

Choose a drink with no sugar and no artificial sweeteners. REVIVR delivers 247mg sodium, 250mg potassium, and 60mg magnesium per can. Zero sugar. Zero calories. Stevia only. Developed in Switzerland for daily use.