Hydration and Dehydration: What Are They and What Are Their Relationships with Sports?

With the advancement of competition, athletes' desire to gain superiority over each other has increased. This superiority will be achievable not only through talent but also through good performance. This situation, which has led to the investigation of methods to enhance performance, has brought the concept of 'hydration' into focus, along with training and nutrition.
In many sports, athletes often conduct their final training sessions in the locations where the competition will take place in order to adapt to the climate conditions and maintain hydration balance during the competition. One of the main reasons for this is to prevent unexpected reactions from the body during the competition by ensuring body adaptation.
But does hydration really have such a significant impact on sports performance? Let's examine it together.
What is Hydration?
Hydration can be simply defined as water and electrolyte balance. Hydration is crucial for the body to maintain normal functions.
Approximately 70% of our body is composed of water, which is divided into compartments within the body. We can see this in more detail in the diagram below.
"Why is water so important?" you might ask.
Let's examine the functions of water in our body and understand why it is so important:

• Water carries nutrients to all cells and our brain, providing them with oxygen.
• Water enables the body to absorb and assimilate minerals, vitamins, amino acids, glucose, and other substances.
• Water cleanses toxins and waste from the body.
• Water helps regulate body temperature.
• Water serves as a lubricant for joints and muscles.

What is Dehydration?
Dehydration, on the other hand, can be simply defined as the disruption of hydration balance.
Hydration balance relies on the equilibrium between daily fluid intake and output. Individuals' daily fluid needs vary significantly.
The fluid needs of individuals depend mainly on three factors:

• Physical activity
• Ambient temperature
• Relative humidity

**In general, for individuals engaging in sports, consuming 50 ml of water per kilogram of body weight is sufficient.
Causes of Dehydration

1. Sweating
2. Illness, high fever
3. Frequency of urination

So, what are the symptoms of dehydration? How can we tell? Let's take a look at the symptoms together:

• Fatigue
• Dry mouth
• Increased thirst
• Decreased urine output and urine color (the table below is one of the easiest and most important indicators to measure the level of dehydration.)
• Dizziness
• Headache

The Relationship between Sports and Dehydration
Especially for athletes, hydration is crucial for optimal performance. A 2% decrease in body weight significantly reduces aerobic performance. A study conducted in 2004 indicated that dehydration reduces performance during endurance exercises through mechanisms such as increased cardiovascular strain due to hyperthermia and decreased blood volume.