H 2 Owesome Round II The Water Group: Kelsey, Alex, and Michael

Where Is Water Stored? Everywhere! Water makes up of 40-70% of body mass in humans  Dependent on age, gender, body composition, and physical activity level Water Throughout the Body Skin: 70% Blood: 83% Brain: 75% Muscle: 75% Bones: 22% Connective Tissue: 60% Fat: 20%

How Is Water Stored? Intracellular Fluid- fluid that is found inside the cell  62-65% of total body water Extracellular Fluid- fluid that is not inside the cells. Serves as a way for waste and nutrients to be transported throughout the body.  35-38% of total body water  Blood plasma accounts for about 20% of extracellular fluid  Interstitial Fluid- fluid that flows within the microscopic spaces between cells  Includes: Lymph, Saliva, fluid in the eyes, fluid secreted by glands and digestive tract, fluid that bathes spinal and cord nerves, and fluid secreted by kidneys and skin

How the Compartments Work Minerals help maintain the fluid levels in the Intercellular and Extracellular Fluid compartments The body regulate the fluid levels of each compartment by sending hormonal messages to the brain and the kidneys. If more fluid is present than desired at the cell, the kidneys make urine by filtering the excess fluid from the blood. Pizza Example:  Sodium in pizza accumulates in Extracellular fluid. Causes water to be pulled from the Intercellular fluid  Cell sensors detect change and signal brain that the cell is dehydrated  Brain signals body to drink more water until both compartments are appropriately filled

Fluid Storage and Exercise Moderate-to-Intense physical training often increases percentage of water in the intracellular compartment  This is because muscle mass typically increases through training and muscle stores a larger water content Single, acute bouts of exercise shifts fluid from plasma to interstitial and intercellular spaces  Caused by increased hydrostatic pressure within the circulatory system

How is Water Consumed? An individual’s water content remains relatively stable over extended periods of time. Average sedentary adult in a neutral environment requires about 2.5L of water daily  Active individuals in humid environments may need 5-10L of water daily Water Sources:  Foods  Liquids  Metabolism

Water From Food Food  Water from food usually accounts for 20-25% of recommended total fluid intake  Fruits and vegetables contain a high amount of water  Butter, oils, dried meats, chocolate, cookies, and other sweets have a low water content.  Foods with 90% or more of their weight from water  Lettuce, raw strawberries, cucumbers, watercress, Swiss chard, boiled squash, green peppers, bean sprouts, watermelon, cantaloupe, celery, and raw peaches

Water From Liquids On average, an individual consumes 41 ounces of water daily Physical activity and thermal stress can increase fluid needs by 5-6 times In the US, majority of water intake is not from plain water, but from a variety of foods and beverages.  Other Beverages: 43.6% of total water intake  Water: 31.4% of total water intake Alcohol is a diuretic. During activities, increased sweating and temperature can contribute to greater water loss  Should drink more water Young children, pregnant and lactating women, the elderly, and people with certain illnesses require increased fluid intakes.

Metabolic Water  Breakdown of macronutrient molecules in energy metabolism form carbon dioxide and water.  Metabolic water provides about 14% of daily water requirements for a sedentary person

Determining Water Consumption Water intake should equal the amount of water loss Water Output  Through urine  The skin  Water vapor through expired air  Feces Water requirement is the amount necessary to balance the water losses (which vary by person) and maintain a tolerable solute load for the kidneys.  Impossible to set a general water requirement. Water need based on differences in metabolism, environment, and activity levels. A Recommended Dietary Allowance (RDA) could not be established because of variability in water consumption need.

Water Recommendations

When Not Enough Water is Consumed Dehydration= inadequate water intake Symptoms of Dehydration:  1% of body weight loss from water= impairs thermoregulation and thirst occurs  2%= Thirst increases. Vague discomfort and loss of appetite  3%= dry mouth  4%= 20-30% loss in work capacity  5%= difficulty concentrating, headache, sleepiness  6%= tingling and numbness of extremities  7%= collapse  10%= life-threatening

Summary Water is stored everywhere! It is stored through intracellular and extracellular compartments Water is consumed through food, liquids, and water metabolism. Rule of Thumb:  If you are thirsty, drink water!

References McArdle, W.D., Katch, F.I., & Katch, V.L. Exercise Physiology: Energy, Nutrition, and Human Performance, 7 th Edition Baltimore, MD. Williams and Wilkins. Nestle Waters. (2015). Water in your body. Retrieved 3 September 2015, from body Unm.edu,. (2015). Water: Nature's Most Important Nutrient. Retrieved 3 September 2015, from Who.int,. (2015). Retrieved 4 September 2015, from