When you need a quick energy boost, reaching for your favorite caffeinated beverage is probably your top choice. But you may be overlooking the most effective drink for improving energy levels. And that drink is water. “While many people turn to caffeine or sugary beverages for a quick energy fix, regular water consumption is a simple and effective way to maintain sustained energy levels,” says EA Stewart, M.B.A., RD, a registered dietitian and owner of Spicy RD Nutrition. 

If you’re skeptical, we get it. After all, drinking a beverage that’s free, accessible and versatile—like water—for energy seems too good to be true. Except it’s not! Keep reading to learn more about the scientifically backed reasons why water should be your top choice for keeping your energy at its peak.

How Water Can Give You More Energy

Keeps Your Body Running Smoothly

You can’t see it, but approximately 60% of your body is made up of water. Your body requires water for important jobs like regulating blood pressure and body temperature, aiding in chemical reactions and transporting nutrients and waste. Because of this, the body is extremely sensitive to fluid variations and will adjust its functions to maintain water balance. When your water stores dwindle, every cell in your body feels the effects, so your energy levels tank.

Protects Against Dehydration

When water is limited or when too many fluids are lost via sweat, you can become dehydrated. What happens next? Without enough water on tap, cells shrink in size. This then prompts signals to the brain that let you know you’re thirsty. At the same time, your brain also tells your kidneys to concentrate urine to prevent additional fluid losses. And you don’t have to lose a lot of fluid for dehydration to kick in. “Even mild dehydration, just a 1% to 2% loss in body water, can leave you feeling tired, sluggish and unfocused,” says Carlette Roberts, a United Kingdom-based registered dietitian and founder of FreshLife.

Improves Alertness and Cognitive Function

Many factors affect how your brain functions, including your hydration status. Mild dehydration has a negative effect on memory, focus and the brain’s ability to complete certain tasks. Conversely, research has found that optimal hydration is associated with improvements in attention and short-term memory in middle-aged and older adults. And when you’re more alert and attentive, you feel more energized.

Improves Physical Performance

Even small water losses can negatively impact your physical performance when you’re working out. For instance, reduced blood volume can cause the heart to work harder to pump blood to working muscles. You may also experience mental fatigue, impaired body temperature regulation and increases in perceived effort, making exercise feel harder than usual.

If you exercise regularly, there’s another indirect way that water helps your energy levels. Optimal hydration can make exercise feel better, so you’re more likely to want to hit the pavement or hop on the bike. And research has shown that physical activity, especially the kind that feels good, can help boost energy levels.

Other Strategies for More Energy

If you’d like more energy (and who wouldn’t?), these dietitian-approved hydration and lifestyle strategies can help.

• Don’t Wait Until You’re Thirsty. Thirst isn’t always a reliable way to gauge your hydration, especially as you get older. Roberts recommends sipping water throughout the day, not just when you feel thirsty. But if you really want to know where your hydration stands, check your pee. “Pale yellow urine is a good sign you’re well-hydrated,” she says.
• Hop on the Scale. Not for fat loss, for water loss. Weighing yourself before and after working out is an easy way to measure fluid losses from sweating. If you’ve lost more than 2% of your pre-workout weight, it’s time to drink up.
• Eat Fluid-Rich Foods. Did you know that food supplies roughly 20% of our daily fluid intake? In addition to drinking plenty of water, fill your plate with water-rich foods, especially fruits and vegetables. Also, keep in mind that, in addition to water, other fluids can help you meet your needs, like tea, coffee and low-fat milk (research shows it’s as hydrating as water!). 
• Have a Hydration Strategy.  This might include setting a timer as a reminder to drink water or putting a glass of water on your desk in a prominent location. Stewart encourages her clients to take a break every hour, get some movement and drink an 8-ounce glass of water to promote hydration. 
• Maintain a Routine. Skipping meals is one of the worst things you can do for your energy levels, says Mandy Enright, M.S., RDN, a registered dietitian and author of 30-Minute Weight Loss Cookbook. “I always emphasize timing, quality and quantity when it comes to maintaining energy levels throughout the day,” she says. Depending on what works for you, that can be three squares a day or smaller, more frequent meals every three to four hours. 
• Eat Balanced Meals. “Besides optimizing water intake, my top recommendation for sustained energy is eating regularly scheduled meals with a balanced mix of protein, healthy fats and high-fiber carbohydrates,” says Stewart. This combination aids in satiety and helps to ensure your blood sugar remains stable, preventing energy crashes after meals. Eating a wide variety of foods also supplies the vitamins and minerals your body needs to stay energized, especially B vitamins, iron, magnesium and zinc.
• Fuel Efficiently. Extreme calorie-cutting can negatively affect your energy levels. Conversely, large, heavy meals that exceed your daily calorie needs can also leave you feeling sluggish. This is especially true with high-fat foods and refined carbs, says Enright. Following your body’s hunger and fullness cues and eating balanced, nutritious meals can help you meet your energy needs without the need to count calories. 

The Bottom Line

Optimal hydration keeps your body and brain running smoothly. Without enough fluids, you may become dehydrated and feel listless, fatigued and mentally fuzzy. Fortunately, drinking water is one of the best ways to hydrate. It also improves cognitive function and enhances physical performance. No wonder dietitians say water is the best drink for more energy. Plus, water is free and readily available, so you can easily add it to your daily routine. How much should you drink? The answer might surprise you. So, grab a water bottle and fill it up!