Water Balance Regulation & How Different Environments Affect Body Water Content

For athletes, keeping water balance in the body is vital for staying competitive in sports that require intense physical activity and motor coordination. Making up 60% of the body, water is essential for allowing the nervous system to transport fluids and nutrients to every cell.

Whenever you're pushing your body to its limits, whether it's due to extreme weather or intense exercise, keeping a water balance in the body will not only save you from the discomfort of dehydration symptoms but also ensures the best athletic performance. Fluid balance and hydration are essential when exercising because it helps regulate many different essential mechanisms — body temperature, the quick absorption of nutrients, lubrication of joints, and even how your muscles are feeling (hydration prevents muscle cramps).

Girl drinking from an Iron Flask water bottle

Why Is Water Balance In the Body Important?

When total water loss equals 2% of your body mass, it can start to impair your athletic performance. This is why it's essential that you understand all the factors that influence water needs. When water balance in the body is off, it can also cause a long list of symptoms related to dehydration — muscle cramps, fatigue, and dry mouth are just some of the warning signs that your fluid intake to water loss is not at a healthy ratio.

There are several ways that you can maintain water balance in the body. We've outlined a few expert-recommended ways to stay hydrated when doing any intensive activities, particularly in extreme climates.

Factors Affecting Water Balance In the Human Body

The body regulates water balance through a system called osmoregulation. About 10 liters of water per day are distributed throughout the organs through this mechanism. And when the body can balance water output with water input, the cells can achieve a healthy state of homeostasis.

The feeling of thirst is also part of osmoregulation. Through a series of neuronal signals from the kidneys, heart, and hypothalamus, protein receptors can detect a decrease in fluids or an increased concentration of sodium in the blood. These signals are sent to the hypothalamus, the brain's thirst center. When fluids are consumed, receptors in the mouth and stomach send signals to the brain and the thirst center gets shut off.

Water Loss

What about other factors affecting water intake? There are several processes the body uses to intake water. Most of the water produced in the body is primarily absorbed from the digestive tract. Another small amount of water is produced in the body when certain nutrients are metabolized. There are other factors that influence water needs, such as water loss in the body, which happens primarily from being excreted in urination from the kidneys. Profuse sweating in hot climates or during vigorous exercise also contributes to water loss. In these instances, you'll need to drink more water than usual.

Calculate Your Sweat Rate

To find out exactly how much additional water you need to drink, you can calculate your sweat rate by taking your pre-exercise body weight and subtracting it from your exercise post-exercise body weight. Then add fluid intake, and subtract urine volume/exercise time in hours. This calculation will give you a wide representation of possible situations with different types of exercise and environmental conditions.

Regulation of Water Balance In the Body

For people doing strenuous exercise in hot climates, an excessive amount of sweating makes the regulation of water balance in the body even more important due to the significant fluid loss. Other factors affecting hydration are cold, high altitude climates, which cause the body to urinate more often, and consequently lead to the loss of fluids. Along with vigorous exercise, heavy clothing will also increase water loss by keeping your core temperature at a high rate.

Stay Hydrated Before, During, and After Workouts

Physical trainers recommend pre-hydrating before a workout, which will make up for any fluid loss from sweating. According to fitness trainers at ISSA, a general rule is to drink about two cups 30 minutes before working out and then one cup of water or sports drink every 15 minutes during your workout.

Calculate Your Daily Water Intake

You can also calculate how much water you should drink per day by your weight. The amount of water a person needs depends on weight — the more someone weighs, the more they need to drink. Simply multiply your weight by 2/3 or 67% to calculate how much water you should drink daily.

You should adjust this number based on how much you are exercising, especially since you lose significant fluids through sweat. A sensible guideline is to add 12 oz of water to your daily total intake for every 30 minutes that you exercise. For example, if you work out for 45 minutes a day, you would add 18 oz of water to your daily amount. And as aforementioned, climate and temperature will also require additional water intake on top of your regular amount.

Keep track of your water intake with a specific container such as a reusable water bottle. Depending on your needs, you can set a goal for how many times you need to finish the container in a day.

As you can see, there are many intricate and complicated processes that must happen within the body in order to maintain a balanced amount of water. With this in mind, you can easily stay healthy and hydrated when you're mindful of your water intake on all your daily adventures.