Optimal Hydration: How Much Water Should a Person Drink on Creatine?

Table of Contents

1. Introduction
2. The Science of Creatine and Its Demand for Water
3. Navigating Creatine Dosing and Corresponding Hydration
4. Practical Strategies for Optimal Hydration While on Creatine
5. Addressing Common Concerns: Creatine, Water Retention, and Dehydration
6. Beyond Creatine: Holistic Wellness and Hydration
7. Conclusion
8. FAQ

Introduction

As dedicated individuals pursuing a life of adventure and wellness, we often seek ways to optimize our physical capabilities and support our active lifestyles. Creatine has long been a cornerstone supplement for many looking to enhance strength, power, and muscle development, earning its reputation as one of the most rigorously studied and effective compounds in sports nutrition. Yet, amidst the excitement of improved performance, a crucial element often gets less attention: hydration. Just as a high-performance engine requires the right fuel and cooling, our bodies, especially when fueled by creatine, demand a precise balance of water to truly thrive.

The question of "how much water should a person drink on creatine" extends far beyond simply mixing a scoop into a glass. It delves into the intricate relationship between cellular function, metabolic processes, and overall well-being. Without adequate hydration, the full spectrum of creatine's benefits can be diminished, and potential discomforts might arise. This isn't just about avoiding a dry mouth; it's about supporting your body's natural functions at a cellular level, ensuring every workout, every adventure, and every day is met with peak vitality.

Here at BUBS Naturals, we believe in a no-BS approach to wellness—simple, effective ingredients that are rigorously tested and certified. Our commitment to supporting your journey mirrors our dedication to giving back, inspired by the legacy of Glen "BUB" Doherty. In this comprehensive guide, we'll dive deep into the science behind creatine and water, provide practical hydration strategies, address common concerns, and show you how to unlock the full potential of your wellness routine. By the end, you'll have a clear understanding of why proper hydration is not just recommended, but essential for anyone incorporating creatine into their regimen.

The Science of Creatine and Its Demand for Water

To truly appreciate the importance of hydration when using creatine, it's helpful to understand what creatine is and how it functions within the body. Creatine isn't some synthetic concoction; it's a naturally occurring organic acid that plays a pivotal role in cellular energy production, particularly in tissues with high energy demands like skeletal muscle, the heart, and the brain.

What is Creatine?

Creatine is primarily synthesized in the liver, pancreas, and kidneys from amino acids, then transported via the bloodstream to various organs for storage. In muscle cells, it largely exists as phosphocreatine (CrP) or creatine phosphate. Think of CrP as a rapidly accessible energy reserve. During short, intense bursts of activity—like lifting heavy weights, sprinting, or performing explosive movements—our muscles demand a rapid supply of adenosine triphosphate (ATP), which is the body's primary energy currency. However, ATP stores are limited and deplete quickly.

This is where creatine steps in. The phosphocreatine system allows for the rapid regeneration of ATP from adenosine diphosphate (ADP). CrP donates its high-energy phosphate group to ADP, quickly converting it back into ATP. This process provides a consistent and immediate energy supply, enabling you to maintain peak performance during high-intensity, short-duration activities. By supplementing with a high-quality product like our Creatine Monohydrate, you can increase your muscle's phosphocreatine stores, thereby enhancing your capacity for strength, power, and overall training performance. Our Creatine Monohydrate embodies our no-BS approach, offering a single, pure ingredient that is effective and easy to integrate into your routine.

Why Creatine Increases Your Body's Fluid Needs

The relationship between creatine and water is fundamental to its effectiveness. Creatine doesn't just work in isolation; it leverages your body's existing systems, many of which are water-dependent.

Cell Volumization: A Key Mechanism

One of the primary ways creatine enhances muscle performance is through its "cell-volumizing" effect. Creatine is an osmotically active substance, meaning it draws water into the muscle cells. When you supplement with creatine, it increases the concentration of creatine within your muscles, which in turn pulls more water into those cells. This phenomenon isn't just about making your muscles appear fuller; it has significant physiological implications.

This increased intracellular hydration (water inside the cells) is thought to be an anabolic signal, meaning it helps stimulate muscle protein synthesis. Essentially, well-hydrated muscle cells create a more favorable environment for growth and repair. For someone committed to their fitness journey, ensuring this cellular hydration is maximized means optimizing the potential for muscle development and recovery. Without sufficient water intake, this beneficial cell volumization cannot occur efficiently, potentially limiting the very effects you're seeking from creatine.

Metabolic Byproducts and Kidney Function

Creatine metabolism produces a waste product called creatinine. While naturally occurring, higher levels of creatine supplementation can lead to a slight increase in creatinine levels, which your kidneys then filter from your blood for excretion in urine. Adequate hydration is paramount to support optimal kidney function. When you drink enough water, your kidneys can efficiently perform their filtering role, preventing the accumulation of metabolic waste products. Consider it like ensuring a clear flow through a filtration system; the more fluid moving through, the better and more efficiently the system can clean itself. Neglecting water intake can place undue strain on these vital organs, potentially hindering their ability to process and eliminate waste effectively.

The Hydrolytic Reactions of Energy Production

Recall how creatine regenerates ATP? This process, specifically the breakdown of phosphocreatine to release its phosphate group, involves hydrolytic reactions. "Hydrolytic" literally means "water-splitting." These reactions are dependent on water molecules to proceed efficiently. Therefore, simply put, if there isn't enough water available, the enzymatic reactions that facilitate ATP regeneration might be less efficient. This highlights how hydration isn't just a side consideration but an integral part of creatine's mechanism of action. Supporting your body with enough water means you're providing the necessary medium for creatine to perform its energy-boosting role effectively.

In summary, creatine supplementation inherently increases the body's fluid needs due to its cell-volumizing effect, the metabolic processing of its byproducts, and its direct involvement in water-dependent energy reactions. Ignoring these increased demands could lead to reduced effectiveness of the supplement and potential discomforts. This is why we champion a holistic approach to wellness, where clean, effective supplements like our Creatine Monohydrate are always paired with foundational practices like diligent hydration.

Navigating Creatine Dosing and Corresponding Hydration

Understanding the interplay between creatine and water is one thing, but translating that into practical, daily habits requires specific guidance. The amount of water you should drink when taking creatine isn't a one-size-fits-all answer; it depends on your dosing strategy, activity level, and individual physiological factors.

The Creatine Loading Phase and Hydration

Many individuals beginning creatine supplementation choose to start with a "loading phase." This involves taking a higher dose of creatine for a short period, typically 5-7 days, to rapidly saturate muscle creatine stores. The goal is to quickly maximize the creatine available for ATP regeneration and cell volumization. A common loading protocol involves consuming around 20 grams of creatine per day, often split into four equal doses of 5 grams each.

During this intensive loading phase, your body's demand for water significantly increases. Imagine rapidly filling a sponge with water; you need a consistent and ample supply to achieve full saturation. Without increasing your fluid intake commensurately, you risk experiencing common discomforts such as muscle cramps, gastrointestinal upset, or a general feeling of dehydration. Each 5-gram dose of Creatine Monohydrate needs a sufficient amount of water to dissolve fully and be absorbed. We generally recommend taking each 5-gram serving with at least 12 ounces (approximately 375 mL) of water to facilitate optimal absorption and reduce potential digestive discomfort.

Considering the total daily intake during a loading phase, which could be 20 grams of creatine, this means consuming at least 48 ounces (over 1.4 liters) of water just with your creatine doses. This is in addition to your baseline daily water needs. For most active adults in a loading phase, aiming for a total daily water intake of 3 to 4 liters (12 to 16 cups) is a solid recommendation. This higher intake supports the rapid cellular uptake of creatine, helps prevent dehydration, and assists your kidneys in managing metabolic byproducts efficiently. This initial push in hydration is a critical step in setting the stage for creatine's long-term benefits.

The Creatine Maintenance Phase and Daily Water Intake

Once the loading phase is complete, or if you opt for a gradual approach, you transition to a "maintenance phase." This involves a lower, consistent daily dose to keep your muscle creatine stores topped up. The typical maintenance dose for Creatine Monohydrate is between 3 to 5 grams per day. While the immediate demand for water with each dose remains important, the overall daily fluid requirement stabilizes compared to the loading phase.

For your daily maintenance dose, we still recommend mixing your Creatine Monohydrate with at least 12 ounces of water. This ensures good solubility and absorption. Beyond that specific intake, your total daily water consumption should be robust. A good general guideline for active individuals taking creatine is to aim for 2.5 to 3.5 liters (approximately 10 to 14 cups) of water per day. This supports continuous muscle hydration, kidney function, and overall physiological processes.

Remember, this is a general recommendation, and individual needs can vary. It’s about consistently providing your body with the fluid it needs to keep your systems running smoothly, allowing your creatine to perform its best. To further support your daily fluid and electrolyte balance, especially when you're engaging in intense physical activity or exploring the outdoors, consider integrating products from our Hydration Collection. Our Hydrate or Die – Lemon or Hydrate or Die – Mixed Berry offer performance-focused electrolytes with no added sugar, perfect for replenishing what your body loses through sweat.

Factors Influencing Individual Water Needs

While general guidelines are helpful, your precise daily water needs are highly individual. Several factors can significantly impact how much fluid you require, especially when supplementing with creatine:

• Body Mass and Composition: Larger individuals, particularly those with more muscle mass (which holds more water), naturally require more water. A 200-pound athlete will need more fluid than a 140-pound individual, even with the same creatine dose.
• Activity Level and Intensity: The more physically active you are, and the higher the intensity of your workouts, the more you sweat and lose fluids. An hour-long, high-intensity training session in a gym, or an adventurous hike, will necessitate greater fluid intake than a sedentary day.
• Environmental Conditions: Hot and humid climates significantly increase sweat rates, leading to greater fluid loss. Conversely, even in cold, dry environments, you can lose substantial water through respiration, often unnoticed. Altitude can also increase fluid needs.
• Dietary Habits: A diet rich in fruits and vegetables, which have high water content, contributes to your overall fluid intake. Conversely, a diet high in processed foods or excessive sodium can increase your body's demand for water.
• Other Supplements and Medications: Certain supplements (like those with diuretic effects) or medications can influence fluid balance, requiring adjustments to your water intake. For instance, high caffeine intake can slightly increase urination, potentially increasing fluid needs.
• Health Status: Underlying health conditions can also affect your hydration requirements, making it crucial to consult a healthcare professional for personalized advice if you have specific health concerns.

Continuously monitoring your hydration status through simple indicators like urine color (aim for pale yellow), thirst levels, and the frequency of urination is key. By being attuned to your body's signals and adjusting your fluid intake based on these factors, you can ensure you're providing optimal support for your creatine supplementation and overall well-being. This personalized approach to hydration aligns with our philosophy at BUBS Naturals: understanding your body's unique needs for peak performance in all your adventures.

Practical Strategies for Optimal Hydration While on Creatine

Integrating enough water into your daily routine, especially with the added demands of creatine, doesn't have to be a chore. It's about establishing consistent habits and being mindful of your body's signals. Here are some practical strategies to ensure you stay optimally hydrated and maximize the benefits of your Creatine Monohydrate.

Daily Water Tracking and Habits

The most effective way to ensure consistent hydration is to make it a seamless part of your day.

• Carry a Reusable Water Bottle: This simple habit is incredibly effective. Having water readily available encourages frequent sips throughout the day. Whether you're at your desk, in the car, or out on a trail, a full water bottle is a constant reminder to hydrate. Our products, like Creatine Monohydrate, are designed to mix effortlessly, making it easy to prepare your supplement directly in your water bottle or shaker cup.
• Set Hydration Reminders: In our busy lives, it's easy to get sidetracked. Utilize technology to your advantage by setting alarms on your phone or using hydration tracking apps. A simple reminder every 60-90 minutes to take a "water break" can make a significant difference, helping you spread your intake evenly rather than trying to chug large amounts at once.
• Start Your Day Hydrated: Begin each morning with a large glass of water, perhaps mixed with your Collagen Peptides or a dash of Vitamin C for an added boost. This kickstarts your hydration for the day and helps compensate for any fluid lost overnight.
• Pair Creatine with Ample Water: As discussed, each dose of Creatine Monohydrate should be taken with at least 12 ounces of water. Make this a non-negotiable part of your supplement routine. For example, if you take creatine before your morning workout, make sure you have a substantial amount of water alongside it.

Our commitment at BUBS Naturals is to provide simple, effective solutions that fit seamlessly into active lifestyles. By adopting these consistent habits, you’re not just drinking water; you’re investing in the optimal performance of your body and the efficacy of your supplements.

Incorporating Hydrating Foods and Beverages

While plain water is the gold standard for hydration, you can also boost your fluid intake through smart dietary choices.

• Eat Water-Rich Foods: Many fruits and vegetables boast a high water content and contribute significantly to your daily fluid needs. Incorporate foods like watermelon, strawberries, oranges, cucumbers, lettuce, celery, and bell peppers into your meals and snacks. These foods also provide essential vitamins, minerals, and fiber, further supporting your overall wellness.
• Be Mindful of Dehydrating Beverages: While we don't advocate for complete avoidance, being aware of beverages that can contribute to fluid loss is important. Excessive alcohol consumption is a known diuretic, as is very high caffeine intake. If you enjoy coffee, consider adding our MCT Oil Creamer – 10 oz Tub for a creamy, sustained energy boost, but balance it with additional water throughout the day. Moderation and conscious choices help maintain your hydration balance.

The Role of Electrolytes

When you're highly active, especially during strenuous workouts or in hot conditions, you lose more than just water through sweat; you also lose essential electrolytes like sodium, potassium, and magnesium. These minerals are crucial for nerve function, muscle contraction, and maintaining fluid balance within your body.

• Replenishing Electrolytes: While adequate water intake is primary, in situations of significant sweat loss, supplementing with electrolytes can be incredibly beneficial. This helps prevent imbalances that can lead to muscle cramps, fatigue, and impaired performance. Our Hydrate or Die – Bundle offers a convenient way to keep your electrolyte levels balanced, supporting fast, effective hydration and muscle function without unnecessary sugars.
• Beyond Workouts: Electrolytes aren't just for elite athletes. Anyone engaging in prolonged physical activity, spending time outdoors in challenging conditions, or even feeling sluggish from everyday demands can benefit from electrolyte support. It's about providing your body with the fundamental building blocks it needs to maintain optimal function, perfectly complementing your Creatine Monohydrate and overall wellness journey.

By consciously adopting these strategies, you're not just passively consuming fluids; you're actively managing your hydration status, ensuring that your body is always primed for performance and recovery. This proactive approach to well-being is at the core of the BUBS Naturals ethos.

Addressing Common Concerns: Creatine, Water Retention, and Dehydration

Despite creatine's widespread use and proven benefits, common misconceptions persist, particularly regarding its effects on body water. It's important to differentiate between beneficial cellular hydration and unwanted bloating, and to understand how proper fluid intake plays a critical role in both.

Understanding Water Retention with Creatine

One of the most frequent concerns people express about creatine is "water retention" or "bloating." It's true that creatine can lead to an increase in body weight when you first start supplementing. However, it’s crucial to understand the type of water retention at play.

Creatine primarily draws water into your muscle cells (intracellular hydration), not between cells or under the skin (extracellular fluid), which is what typically causes a puffy or bloated appearance. This intracellular fluid shift is part of how creatine exerts its positive effects, contributing to cell volumization that can stimulate muscle protein synthesis and make muscles appear fuller. It’s a functional, beneficial water retention that supports muscle growth and performance, not the undesirable kind.

Most people experience a temporary increase of a few pounds in water weight during the initial loading phase. This typically stabilizes after the first week or two as the body adapts to the increased creatine levels. Studies have consistently shown that while creatine does impact water distribution in the short term, it generally has no long-term effect on total body water or body composition beyond increased lean muscle mass.

The key to minimizing any undesirable feeling of "puffiness" and ensuring beneficial intracellular hydration is, paradoxically, to drink plenty of water. When your body is dehydrated, it tends to hold onto water more desperately in certain areas as a survival mechanism. Adequate hydration allows creatine to efficiently pull water into muscle cells where it's needed, while also ensuring there's enough fluid for all other vital bodily functions. This balance is what we strive for with our clean, simple ingredients, like our Creatine Monohydrate, which supports your body's natural processes effectively.

Preventing Dehydration While Supplementing

While creatine itself does not directly cause dehydration, it increases your body's demand for water, making you more susceptible to dehydration if your fluid intake doesn't match this increased need. Dehydration occurs when your body loses more fluids than it takes in, leading to a range of symptoms that can significantly impair your physical and cognitive performance.

Signs to watch out for include:

• Dark Urine: This is often the most straightforward indicator. Aim for pale yellow to clear urine.
• Increased Thirst and Dry Mouth: Your body's direct signal for more fluid.
• Fatigue and Weakness: Reduced blood volume from dehydration can make you feel sluggish.
• Headaches and Dizziness: Common symptoms of mild to moderate dehydration.
• Reduced Urine Frequency and Volume: An obvious sign your body is conserving fluids.
• Muscle Cramps: A classic symptom of electrolyte imbalance often triggered by dehydration, especially during exercise.

Preventing dehydration is about being proactive with your fluid intake. This means consistently sipping water throughout the day, especially around your workouts, and consuming enough to offset both baseline needs and the increased demand from creatine. Our Hydration Collection, featuring products like Hydrate or Die – Mixed Berry, is specifically designed to support this critical balance, offering clean electrolytes to help you replenish what you lose.

The BUBS Naturals approach is centered on empowering you to live a full life of adventure and wellness. This commitment means providing you with high-quality, third-party tested supplements like our Creatine Monohydrate and equipping you with the knowledge to use them effectively and safely. By prioritizing hydration, you're not only maximizing the benefits of creatine but also supporting your overall health and resilience.

The BUBS Naturals Approach: Clean and Purposeful Hydration

At BUBS Naturals, our journey began with a simple, yet profound, mission inspired by our friend Glen “BUB” Doherty: to live a life of adventure, wellness, and purpose. This philosophy permeates everything we do, from our commitment to sourcing clean, high-quality, natural ingredients to our rigorous third-party testing, including NSF for Sport certification. We believe in a no-BS approach, offering only simple, effective ingredients that truly make a difference in your wellness journey.

When it comes to hydration, this commitment translates into products designed to support your body’s natural functions without unnecessary additives. Our Creatine Monohydrate is a testament to this, providing pure, single-ingredient support for your strength and performance goals. Paired with adequate water, it's a foundational element of a robust wellness routine.

Furthermore, our dedication extends beyond just physical well-being. A significant part of our purpose is giving back. We proudly uphold our 10% Rule, donating 10% of all profits to veteran-focused charities in honor of Glen "BUB" Doherty's legacy. So, when you choose BUBS Naturals, you're not only investing in your own adventure and wellness but also contributing to a greater purpose, supporting those who have served. This holistic view of wellness, encompassing both personal health and communal support, defines who we are.

Beyond Creatine: Holistic Wellness and Hydration

While creatine and hydration are powerful allies for physical performance, they are just two pieces of a larger puzzle that constitutes true holistic wellness. At BUBS Naturals, we encourage a comprehensive approach that nourishes your body from all angles, supporting everything from joint health to mental clarity, all while maintaining optimal hydration.

Supporting Your Body with Essential Nutrients

Our bodies are complex systems, and while creatine can boost energy for intense workouts, other supplements play equally vital roles in overall health and recovery. Integrating a range of clean, functional nutrients ensures your body has everything it needs to perform, recover, and thrive.

For instance, consider the structural integrity of your body. Our Collagen Peptides, derived from grass-fed, pasture-raised sources, offer hydrolyzed collagen (Types I & III) to support healthy joints, skin, hair, and nails. Collagen mixes effortlessly into your morning coffee or smoothie, becoming a simple daily habit that contributes to your body's natural repair processes. This can be particularly beneficial for active individuals who put stress on their connective tissues during training.

For sustained energy and mental clarity, especially during long days or challenging adventures, our MCT Oil Creamer – 10 oz Tub is an excellent addition. Made from clean coconut oil, it provides medium-chain triglycerides that are easily converted into ketones, offering a steady fuel source. It’s perfect for adding to coffee or shakes, elevating your morning ritual.

Furthermore, supporting your immune system and natural collagen formation is always a smart move. Our Vitamin C supplement delivers 500 mg of Vitamin C with citrus bioflavonoids to support antioxidant activity and overall cellular health. And for those looking for digestive and general wellness support, our Apple Cider Vinegar Gummies offer the benefits of liquid ACV, including "the Mother," in a convenient, delicious form. Each of these products reflects our commitment to science-backed, effective ingredients that seamlessly integrate into a healthy, adventurous lifestyle.

The Adventure of Wellness

At BUBS Naturals, we don't just sell supplements; we advocate for a lifestyle. A life of adventure means pushing your limits, exploring new horizons, and embracing challenges, whether that's summiting a mountain, conquering a new workout, or simply mastering a new skill. Wellness isn't a destination; it's an ongoing journey of mindful choices that support your body and mind.

Hydration is a foundational pillar of this journey. It’s the invisible force that underpins every aspect of your performance, recovery, and overall vitality. Just as our founder, Glen "BUB" Doherty, lived a life full of purpose and adventure, we believe in equipping you with the purest, most effective tools to live yours.

By understanding the synergy between our premium Creatine Monohydrate and diligent hydration, you're not just taking a supplement; you're adopting a conscious approach to your health. This mindful attention to your body's needs ensures that you are always ready for whatever adventure awaits, feeling your best, inside and out. It’s about more than just physical gains; it’s about nurturing a resilient body and mind, prepared for the full spectrum of life’s demands.

Conclusion

The journey toward peak physical performance and overall wellness is multifaceted, but few elements are as fundamental and interconnected as creatine supplementation and robust hydration. We've explored how creatine, a powerful ally for strength, power, and muscle growth, significantly increases your body's demand for water through cellular volumization, metabolic processes, and energy regeneration. Whether you're in a creatine loading phase or maintaining a consistent daily dose, ensuring adequate fluid intake is not just beneficial, but absolutely essential for maximizing creatine's effectiveness and supporting your body's natural functions.

We've detailed practical strategies, from carrying a water bottle to incorporating hydrating foods and considering electrolyte support with our Hydration Collection, to help you seamlessly integrate optimal hydration into your daily routine. Dispelling myths about water retention, we've highlighted that the cellular hydration driven by creatine is a positive, anabolic signal, provided you’re giving your body the fluids it needs.

At BUBS Naturals, our mission is to empower your adventurous spirit with clean, science-backed supplements that embody our no-BS approach. Our Creatine Monohydrate is a testament to this commitment, offering pure, effective support for your strength and performance goals. We believe in living a life of purpose, and a part of that purpose is ensuring our bodies are well-equipped for every challenge and adventure.

By prioritizing proper hydration alongside your creatine regimen, you're investing in a holistic approach to wellness that enhances performance, aids recovery, and supports vital bodily functions. Take the next step in optimizing your routine. Explore our Creatine Monohydrate and discover how our commitment to quality ingredients can elevate your wellness journey, helping you feel the BUBS difference. Together, let's embrace a life where every scoop and every sip contributes to a stronger, more vibrant you, all while honoring the legacy of giving back.

FAQ

Q1: What happens if I don't drink enough water when taking creatine? A: If you don't drink enough water while taking creatine, you may experience several drawbacks. The primary benefit of creatine, which involves drawing water into muscle cells for cell volumization and protein synthesis, may be diminished. Additionally, you could face increased risks of dehydration symptoms like muscle cramps, fatigue, headaches, and general discomfort. Your kidneys, which process creatine's metabolic byproducts, may also have to work harder without sufficient fluid.

Q2: Can creatine cause bloating or water retention, and how is that affected by water intake? A: Creatine can cause a temporary increase in body weight due to water retention, but this is primarily intracellular (water drawn into muscle cells), which is beneficial for muscle function and growth. This is different from extracellular bloating or puffiness. Paradoxically, drinking more water helps minimize any undesirable feelings of bloat by allowing creatine to efficiently pull water into muscle cells while ensuring overall fluid balance for other bodily functions. Adequate hydration helps your body adapt and manage these fluid shifts effectively.

Q3: How much water should I drink with each dose of creatine? A: For optimal absorption and to minimize the potential for digestive discomfort, we recommend mixing each 3-5 gram dose of Creatine Monohydrate with at least 12 ounces (approximately 375 mL) of water. If you are in a creatine loading phase taking multiple doses, ensure each individual dose is taken with this amount of water.

Q4: Beyond just water, what other hydration strategies can support my creatine use and overall wellness? A: In addition to plain water, incorporating water-rich foods like fruits and vegetables into your diet can significantly boost your fluid intake. For active individuals or those in warmer climates, supplementing with electrolytes can be crucial to replenish minerals lost through sweat and maintain fluid balance. Our Hydrate or Die – Lemon offers a clean, sugar-free way to support effective hydration and muscle function. Additionally, being mindful of dehydrating beverages like excessive caffeine or alcohol can help maintain your body's hydration levels.