Water is the most important nutrient. Along with carbohydrates, fats, and protein, water is considered a macronutrient – something the body needs in large amounts. And, this is even more important when it comes to athletic performance.
As little as a 1% reduction in body water content is enough to hamper athletic performance – maybe as little as even 0.5%. Â Water does not provide any calories directly to the body, but it moves nutrients and oxygen through the bloodstream and helps to remove toxins and waste from the body.
Remember, the body is mostly water so don’t shortchange yourself of this important nutrient. The average human body is 60% to 65% water.
Sources of Body Water
Where does the body obtain its water? Seems like an easy question, and in some ways it is. There are four main sources the body can tap into to get water. They are:
- Liquids
- Food
- Metabolic water
- Glycogen bound water
Liquids
The liquid we drink is the most obvious and prevalent way we feed the body water. Liquids account for two-thirds of our body water – probably less than you thought.
Food
All food contains solids and at least some water. The water content of food varies with water making as much as 80% to 95% of fruits and vegetables. Dry grains and pasta contain about 3% to 5% water with meats ranging from 45% to 75% depending on how well they are cooked. Believe it or not, food accounts for nearly the remaining one-third of our body water content – probably more than you thought.
Metabolic Water
The act of converting food into energy produces small amounts of water, too. The amount depends on how active you are, but about 10 ounces are generated through metabolism – nearly one soft drink.
Glycogen Bound Water
Glycogen is a storage form of glucose and is found in all cells of the body with most glycogen being stored in the muscles. There are about 4 ounces of water stored with each ounce of glycogen. As glycogen is converted into glucose to supply the exercising body with energy water becomes available for use. During intense exercise about 16 ounces of water can be released by glycogen.
Water Loss
Water is lost through sweat, breathing, urine, and feces, but is affected by several other factors related to athletic performance. These other factors include:
- Air temperature
- Humidity
- Intensity of exercise
- Duration of exercise
- Clothing being worn during exercise
- Individual’s sweat rate
How Much Water Do You Need?
How much water you need is affected by many factors but there are simple rules or guidelines you can follow. Don’t wait until you are thirsty to drink water. You already have a water deficit by the time the thirst response kicks in.
One rough rule is to consume in ounces half your body weight in pounds. If you weigh 150 pounds then you would need to consume 75 ounces of water a day.
Another easy guide to determine if you are well hydrated is how frequently you urinate. When well hydrated you should be urinating every 1 1/2 to 2 hours.
You can also base your water intake based on the number of calories you burn. You can estimate your daily energy expenditure by going to this post.
Daily Energy Expenditure                               Daily Water Intake
2,000 calories                                                                          64 to 80 ounces
3,000 calories                                                                           102 to 118 ounces
4,000 calories                                                                          138 to 154 ounces
5,000 calories                                                                          170 to 186 ounces
6,000 calories                                                                         204 to 220 ounces
So be sure to stay tanked up with water to get the most from your athletic performance. During the hot summer months, staying hydrated is extremely important to ward off heat illness.
Originally published 4/25/14.
Update 7/20/2023.
