FSHN 2650: Water & Exercise

Iowa State University - FSHN 2650

Intracellular fluid

Fluid inside cells, makes up 2/3 of total body water

Interstitial fluid

Fluid between cells in the spaces surrounding tissues, part of extracellular fluid

What are the 5 major functions of water in the body?

1. Transport and reactive medium

2. Waste removal

3. Lubricant

4. Structure

5. Thermoregulatory mechanisms

Transport of nutrients example:

Blood carries glucose and oxygen to cells

Waste removal example:

Urine eliminates toxins and metabolic waste

Lubrication example:

Synovial fluid in joints

Structure example:

Cushioning and protection for organs

Thermoregulation example:

Sweating to cool the body

How’s water aid in thermoregulation during exercise?

Water helps by ___ and ___ which ___ the body

sweating, evaporation, cool

Training improved temperature regulation by increasing ___ ___ and improves ____ adaptation.

sweat rate, cardiovascular

During training, there is ____ of sweat glands.

hypertrophy

Dehydration decreases performance because it ___ ___ ___.

reduces blood volume

Dehydration decreases performance because of decreased:

skin blood flow

sweat rate

heat dissipation

Dehydration decreases physical performance because of increased:

core temperature

rate of muscle glycogen use

Fluid loss can be monitored by:

• Body weight changes before and after exercises

• Urine color

Is thirst a good indicator of dehydration, why or why not?

No, it’s a LAGGING indicator, you’re already dehydrated.

___ ___ regulates blood volume and pressure.

antidiuretic hormone (ADH)

ADH is released from the ___ ___ in response to low blood volume.

Pituitary gland

ADH decreases ___ ___ by the kidneys.

water excretion

ADH causes blood vessels to ___.

constrict

___ and ___ inhibit ADH, leading to increased urine output causing ___.

Alcohol, caffeine, dehydration

Aldosterone is secreted from the ___ ___.

Adrenal glands

Low ___ ___ stimulates the adrenal glands to secrete ___

blood pressure, aldosterone

Aldosterone increases ___ ___ by the kidneys.

sodium reabsorption

A situation in which someone would consume a fluid replacement drink:

Endurance athletes; intense exercise lasting longer than an hour

A typical sports drinks has 6-8% of ___, ___, and ___.

carbs, potassium, sodium

Water is appropriate for ___ duration exercise.

short

How are liquid meals different from fluid replacement drink?

Liquid meals also contain protein, fats, and other nutrients.

High concentrations of carbohydrates slow ___ ___ which can delay hydration

gastric emptying

Electrolytes are important in fluid replacement drinks because they increase:

rate of water uptake

palatability

retention of fluid

Electrolytes are important in fluid replacement drinks because they maintain ___.

thirst

Electrolytes are important in fluid replacement drinks because they prevent:

Hyponatremia and cramps