October 10, 2026

How Much Water Should You Drink During a Workout? A Simple Guide

Hydration is the cheapest performance upgrade in the gym. Even mild dehydration can make a workout feel harder than it should. Yet most of us either forget to drink or gulp half a litre at the end.

Below is a simple framework based on widely used sports-nutrition guidance. Treat it as a starting point: needs vary with body size, sweat rate and climate. If you have a medical condition, check with your doctor.

Quick takeaways

Start hydrated: drink roughly 400–600 ml of water about 2 hours before training.
During exercise, sip about 150–250 ml every 15–20 minutes rather than gulping at the end.
Afterwards, keep drinking steadily, especially after a sweaty session in a non-AC gym.
Your urine colour is a free, easy check: pale yellow is the goal.

Before your workout

Walking into the gym already thirsty puts you behind before you start. Aim for about 400–600 ml in the two hours before you train. If you train early in the morning, a glass on waking plus a few sips on the way is a realistic version of this. Our morning routine guide shows how to build it in.

During your workout

A commonly cited range is 150–250 ml every 15–20 minutes of exercise. For a one-hour session that is roughly 0.6 to 1 litre. Heavy sweaters, outdoor runners and anyone training in Indian summer heat should aim for the upper end.

The practical trick: put the water where you can see it. A 1200 ml tumbler beside your bench is a visual timer. If it’s still full at the halfway point, you know you’re behind.

After your workout

Keep sipping for the next couple of hours rather than downing everything at once. If you weigh yourself before and after a long, sweaty session, the difference is mostly water you need to replace over the following hours.

Water or electrolytes?

For a typical 45–60 minute gym session, plain water is enough for most people. For long sessions (90 minutes or more), outdoor training in heat or very heavy sweating, an electrolyte drink can help. Stainless steel tumblers handle electrolyte and lemon water fine. Just rinse them the same day.

A simple daily target

Time	Approx. amount	Easy way to hit it
On waking	250–500 ml	Glass of warm or room-temperature water
2 hrs before training	400–600 ml	Half a 1200 ml tumbler
During a 1-hr session	600 ml–1 litre	Most of one tumbler
Rest of the day	Steady sips	Refill once at work

That’s roughly two to three full 1200 ml tumblers across a training day. It is easy to count, which is why big tumblers have become a gym staple.

Keep it cold, so you actually drink it

There’s a reason people drink more when the water is cold: it simply tastes better mid-workout. A vacuum-insulated tumbler such as the Miora Ember keeps water cold for 11 hours and iced for up to 20 hours. Fill it with ice in the morning and it is still cold after an evening session.

Make hydration visible

The Ember 1200 ml makes the maths easy: two to three fills a day. It has a handle, a reusable straw and a 3-way lid for sips or gulps.

Shop the Ember tumbler

Frequently asked questions

How much water should I drink during a 1-hour gym session?

A common guideline is 150–250 ml every 15–20 minutes, which is about 0.6 to 1 litre for an hour. Drink more in hot or humid conditions.

Is cold water bad during exercise?

No. For most healthy people cold water is fine during exercise, and many find it easier to drink more of it.

Do I need electrolytes for gym workouts?

For typical sessions under an hour, water is usually enough. Long, hot or very sweaty sessions may benefit from electrolytes.

How do I know if I’m drinking enough water?

Pale yellow urine and not feeling thirsty are simple signs. Dark urine, headaches and fatigue can mean you need more water.

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