FitStart Guide
Hydration
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Hydration plays an important role in maintaining the body's normal functions, supporting physical performance, regulating temperature, and transporting nutrients throughout the body.
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Understanding hydration starts with knowing why water is essential, how much fluid the body needs, and what can happen when fluid intake is insufficient. Electrolytes also play an important role in maintaining fluid balance and supporting normal bodily functions.
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The sections below introduce the importance of hydration, explain dehydration and its effects, and explore the role of electrolytes in maintaining proper fluid balance.
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Introduction
What is hydration & why is it important?
Hydration refers to the process of providing the body with adequate fluids, notably water. Water is crucial for our bodily functions and makes up about 67% of our body weight. It is the groundwork for bodily fluids and survival.
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The human body requires water for various tasks, including the regulation of body temperature, the lubrication of joints, nutrient delivery, infection prevention, and waste excretion. Without it, vital organs cannot properly function and life would be impossible.
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Proper hydration is crucial for exercise as well. People such as athletes and yourself must stay properly hydrated before, during, and after exercise, primarily due to the loss of fluid and sodium through sweat. Keeping up with water intake can keep your performance, endurance, breathing, and mood at its best [1] [3] [4] [5].
Men
Women
13-16
cups
9-11
cups
How much water do you need?
Replenishing your water supply is necessary due to daily processes such as sweating, excreting waste, and respiration. The amount of water you need to drink each day varies with each individual, relying on factors such as age, weight, metabolism, and exercise.
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Generally, women should aim for around 9-11 cups of fluids on per day while men should aim for 13-16. This can come from water and other beverages as well as fruits and vegetables. To meet this fluid intake, carry a reusable water bottle with you daily, prioritize water over sweet or sugary drinks, and add fruits to your diet more often [1] [3] [4] [5].
Dehydration
What is dehydration & how does it affect you?
Dehydration occurs when you fail to drink sufficient amounts of water, which has negative effects on both your health and performance. Running low on water reserves can adversely affect your flexibility, speed, endurance, breathing, and mood.
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Symptoms of dehydration include excessive thirst, headaches, dry skin/mouth, darker urine, muscle cramping, lightheadedness or fatigue, and an increasing heart rate. If the issue is not resolved, and dehydration worsens, this may lead to confusion and dizziness, fainting, and irregular breathing [4] [5].
Thirst
Headaches
Dryness
Dark Urine
Cramps
Fatigue
Electrolytes
What is dehydration & how does it affect you?
Electrolytes are substances with either a positive or negative electrical charge when dissolved in water. Examples include sodium, chloride, potassium, phosphate, calcium, and magnesium, each with their own properties and specific function. Therefore, it is crucial to consume them all adequately and in moderation.
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Nearly every fluid and cell in the human body contains electrolytes, as they help regulate chemical reactions, pH, and fluid balance. They also support the function of the heart, muscles, nerves, and brain.
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In terms of sports and exercise, we usually refer to sodium and chloride. Adding these electrolytes to water or consuming sports drinks can help replenish minerals lost through sweat. In turn, this improves nerve signaling and nutrient absorption [2] [5].
Increased HR
References
[1] Centers for Disease Control and Prevention. (2026a, March 5). About water and healthier drinks. Healthy Weight and Growth. https://www.cdc.gov/healthy-weight-growth/water-healthy-drinks/index.html
[2] Cleveland Clinic. (2021, September 24). Electrolytes. https://my.clevelandclinic.org/health/diagnostics/21790-electrolytes
[3] Harvard T.H. Chan School of Public Health. (2017, September 28). The importance of hydration. Harvard T.H. Chan School of Public Health News. https://hsph.harvard.edu/news/the-importance-of-hydration/
[4] National Institutes of Health. (2023, May). Hydrating for health. NIH News in Health. https://newsinhealth.nih.gov/2023/05/hydrating-health
[5] Sports and Hydration for Athletes: Q&A with a Dietitian. (2026, April 20). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/expert-qa/sports-and-hydration-for-athletes