Is Water or Drinks Better for Hydration?

January 12, 2026 •

4 min read

According to a study from Scotland's St. Andrews University, beverages with small amounts of sugar, fat, or protein can keep you hydrated for longer than plain water. This might seem counterintuitive if you've always believed that plain water is the ultimate hydrator, so the question of whether water or drinks are better for hydration is more complex than it appears.

Quick Summary

This article explores the debate between water and other beverages for hydration, detailing the benefits and drawbacks of each. It provides practical guidance on how to choose the right fluids for different scenarios, considering factors like intensity of exercise, duration, and personal health needs.

Key Points

Plain Water is Best for Daily Hydration: For general, day-to-day needs and moderate activity, plain water is the healthiest, calorie-free option to replenish fluids.
Sports Drinks Serve a Specific Purpose: For prolonged, high-intensity exercise (over an hour), sports drinks can be beneficial by replacing electrolytes and providing energy, but are often unnecessary for casual exercisers.
Nutrients Can Improve Sustained Hydration: Beverages with small amounts of sugar, fat, or protein (like milk or oral rehydration solutions) can provide more sustained hydration than plain water, as they slow stomach emptying and improve absorption.
Sugary and Alcoholic Drinks Can Dehydrate You: High-sugar beverages can worsen dehydration, while alcohol acts as a diuretic, inhibiting vasopressin and increasing water loss.
Caffeine's Diuretic Effect is Mild: Moderate consumption of caffeinated drinks like coffee or tea does not cause dehydration in habitual consumers and can contribute to overall fluid intake.
Listen to Your Body, Not Just the '8 Glasses' Rule: Your personal hydration needs vary based on factors like activity level, weight, and climate. Trusting your thirst cues and monitoring urine color are practical approaches.

The Undisputed King: The Power of Plain Water

For most people in most situations, plain water is the gold standard for hydration. It is calorie-free, readily available, and contains no added sugars or artificial ingredients. The body uses water for countless critical functions, from regulating temperature to cushioning joints, and it is the most natural way to replenish fluids lost through daily activities. The Centers for Disease Control and Prevention (CDC) notes that replacing sugary drinks with water is an effective way to reduce caloric intake and prevent health issues linked to excessive sugar consumption.

Beyond simple rehydration, water is essential for overall cellular health, waste elimination, and nutrient transport. While the '8 glasses a day' rule is a myth, consuming water steadily throughout the day is crucial, as the body cannot store it for long periods.

When to Consider a Drink Beyond Water

While water is sufficient for daily hydration, there are specific scenarios where other drinks might be a more strategic choice. This often depends on the duration and intensity of physical activity, as well as external factors like heat and individual needs.

During high-intensity exercise: For prolonged physical activity (over an hour) or intense exercise, sports drinks containing carbohydrates and electrolytes can be beneficial. They help replenish energy stores and replace sodium and potassium lost through sweat. For non-athletes, however, sports drinks offer unnecessary sugars and calories.
For enhanced absorption: A 2019 study published by CNN highlighted research from St. Andrews University, which found that beverages with small amounts of sugar, fat, or protein, such as milk and oral rehydration solutions, can provide longer-lasting hydration than plain water. This is because these components slow down the rate at which fluid leaves the stomach, prolonging the absorption process. Oral rehydration solutions are particularly effective for rehydration during illness.
As a flavorful alternative: If the taste of plain water is a barrier to adequate fluid intake, infusions of natural fruit or vegetables (like lemon, cucumber, or watermelon) can make drinking water more appealing without adding sugars. Herbal teas are another good option for adding variety and hydration.

The Negative Effects of Sugary and Caffeinated Drinks

Many popular drinks, while fluid-based, can actually hinder optimal hydration. High-sugar beverages like soda and sweetened juices can pull water from the body's cells to help metabolize the sugar, potentially worsening dehydration. They also contribute excess calories and are linked to health issues like weight gain and diabetes.

Caffeinated drinks like coffee and tea have a mild diuretic effect, but moderate consumption does not lead to dehydration. However, excessive intake (more than 400 mg daily) can cause jitteriness and other side effects. Alcohol, on the other hand, is a well-known diuretic that can cause significant dehydration by suppressing the antidiuretic hormone vasopressin.

Comparison Table: Water vs. Drinks for Hydration


Feature	Plain Water	Sports Drink	Milk	Oral Rehydration Solution
Effectiveness	Excellent for daily use and moderate activity.	Ideal for high-intensity, prolonged exercise.	Provides longer-lasting hydration due to nutrients.	Highly effective for rapid rehydration, especially during illness.
Nutrient Content	None (unless mineral water).	Electrolytes (sodium, potassium), carbohydrates.	Electrolytes, protein, fat, lactose, calcium, vitamin D.	Sodium, potassium, and a specific amount of sugar.
Caloric Value	Zero calories.	Varies, often high in sugar and calories.	Varies (e.g., skim, whole), contains calories.	Low to moderate calories.
Best For...	General hydration, low to moderate exercise.	Endurance athletes, intense workouts (>1 hr).	Post-exercise recovery, sustained hydration.	Illness (vomiting, diarrhea), severe dehydration.
Drawbacks	May be less effective for prolonged activity electrolyte replacement.	Can contain high levels of sugar and additives.	Contains fat and calories, not suitable for everyone.	Can be unpalatable due to high salt content.

Making the Right Hydration Choice for You

The right drink for hydration isn't a one-size-fits-all answer. For the vast majority of people, plain water is the best and healthiest choice for daily fluid intake. It is calorie-free and fulfills the body's essential hydration needs without introducing unnecessary sugars or additives.

However, in specific circumstances, such as during or after prolonged, high-intensity exercise, or when ill, other beverages can offer distinct advantages. Sports drinks can help replenish energy and electrolytes quickly, while drinks like milk or oral rehydration solutions provide a more sustained hydration effect.

It's important to be mindful of beverage choices, as many popular options, particularly those high in sugar, can negatively impact health and even worsen dehydration. Focusing on water and healthy, low-sugar alternatives is a simple but effective strategy for maintaining optimal hydration.

Practical Hydration Tips

Listen to your body: While you shouldn't wait until you're very thirsty to drink, your body's thirst cues are a good indicator of your general hydration needs.
Eat your water: Water-rich foods like fruits and vegetables (watermelon, cucumber, oranges) contribute significantly to your total fluid intake.
Monitor urine color: A pale yellow color indicates proper hydration. Darker urine suggests you need to increase your fluid intake.
Stay consistent: Sip fluids regularly throughout the day rather than drinking large amounts all at once.

Ultimately, understanding the specific context of your hydration needs—whether it's daily maintenance or intensive recovery—empowers you to make the most informed and beneficial choice for your health.

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Conclusion: Water Reigns Supreme, with Strategic Exceptions

For day-to-day hydration, plain water is the superior choice, delivering essential fluids without the added calories and sugars found in many other drinks. It supports all bodily functions and is the most natural way to stay quenched. However, for those engaging in intense, prolonged exercise, or during periods of significant fluid loss (like illness), beverages formulated with electrolytes and carbohydrates offer targeted, effective replenishment. Mindful choices are key; avoid sugary beverages that can worsen dehydration and prioritize water-rich foods. By tailoring your drink choice to your specific needs, you can ensure optimal hydration and well-being.

Additional Hydration Resources

Harvard Health Publishing: How much water should I drink a day? - Offers detailed guidance on daily water intake based on various factors and addresses hydration myths.

Frequently Asked Questions

No, moderate coffee consumption does not cause dehydration in people who regularly drink it. While caffeine has a mild diuretic effect, studies have shown that the fluid from coffee contributes to your total daily fluid intake, similar to water.

No, sports drinks are not better than water for everyone. For most people and moderate activity, plain water is sufficient. Sports drinks are primarily useful for endurance athletes engaging in prolonged, high-intensity exercise to replace electrolytes and fuel.

According to research from St. Andrews University, beverages like milk and oral rehydration solutions can be more hydrating than plain water over a longer period. The fat, protein, and sugar content in these drinks helps slow gastric emptying, allowing for more sustained fluid absorption.

Yes, it is possible to drink too much water, a condition called hyponatremia. This occurs when drinking excessive water dilutes the body's sodium levels, which can be dangerous, especially for endurance athletes who also lose sodium through sweat.

Sugary drinks can actually worsen dehydration because the body requires more water to metabolize the sugar they contain. This effect, combined with the often-present caffeine, can cause a net loss of fluid from the body.

Yes, a significant portion of your daily fluid intake can come from foods, especially water-rich fruits and vegetables like watermelon, cucumbers, oranges, and soups.

Oral rehydration solutions are particularly recommended for treating dehydration caused by illness, such as vomiting or diarrhea, as they contain precise ratios of electrolytes and sugar that optimize fluid absorption.