Chapter 7 Water and Electrolytes
The extracellular fluid (ECF) is referred to as the "gateway" because water must pass through the ECF to reach cells. True False
True
Through osmosis, water moves from areas of low solute concentration to areas of higher solute concentration. True False
True
The addition of water to the body is primarily accomplished through metabolism. True False
False
The condition of euhydration is when there is an insufficient amount of water in the body to meet physiological demands. True False
False
The main electrolyte lost in sweat during exercise is potassium. True False
False
All body tissues contain approximately 75% water. True False
False
Athletes who train and perform in the water, such as swimmers and water polo players, rarely sweat while in the water. True False
False
Dehydration and hypohydration can be used interchangeably because they both refer to the process of losing water. True False
False
Good advice to athletes who exercise in hot, humid conditions is to drink as much as possible before and during exercise. True False
False
Heavy sweating results in a loss of plasma water and a decrease in plasma sodium concentration. True False
False
In the U.S., the amount of caffeine contained in an energy beverage must be stated on the label. True False
False
It is recommended that athletes avoid caffeine-containing beverages because of the negative effect these beverages have on fluid and electrolyte balance. True False
False
The use of "endurance formula" sports drinks is not an effective strategy for replacing sodium lost during prolonged exercise. True False
False
The water found in the ICF and the ECF remains static. True False
False
As a rule of thumb, athletes who sweat heavily and lose large amounts of sodium should consume approximately _____ g of sodium per hour. 0.25 0.5 1 1.5
1
Approximately how much sweat can an athlete lose each hour when exercising in a hot and humid environment? 1 milliliter per hour 1 liter per hour 1 gallon per hour 25 cups per hour
1 liter per hour
On average, an adult's body contains approximately ____ % water (by weight): 20 40 60 80
60
As a rule of thumb for athletes, experts recommend a post-exercise fluid intake as soon after exercise as practical of approximately ____. 0.5 L of fluid per kg body weight lost 1.0 L of fluid per kg body weight lost 1.5 L of fluid per kg body weight lost 1 pint of fluid for each pound of weight lost
1.5 L of fluid per kg body weight lost
Which athlete is most likely to suffer from hyponatremia? A team athlete such as a football player A strength athlete such as a body builder A slow marathon runner A soccer player
A slow marathon runner
As a rule of thumb, the American College of Sports Medicine recommends a fluid intake at least four (4) hours prior to exercise of approximately ____. 240 ml 500 ml 5-7 ml/kg 10-15 ml/kg
5-7 ml/kg
It would be inappropriate to use scale weight to monitor exercise-related fluid loss and subsequent rehydration with which of the following athletes? Endurance athlete exercising in the heat Endurance athlete exercising in humid conditions Strength athlete Athlete struggling with body image
Athlete struggling with body image
What is the primary source of sodium in the average American diet? Using a salt shaker to add sodium to food Consuming food and fluid that naturally contain sodium Consuming processed food Consuming foods such as milk, vegetables, and grains
Consuming processed food
An athlete's pre-exercise weight is 163 pounds. His post-exercise weight is 161 pounds. What does this two (2) pound weight loss represent? Fat loss Loss of muscle mass Fluid loss Lean body mass
Fluid loss
What is interstitial fluid? Fluid surrounding the cells Any fluid associated with the cardiovascular system Any fluid that does not contain cations Plasma portion of the extracellular fluid compartment
Fluid surrounding the cells
What effect would glycerol loading have on an athlete's body weight? No effect on body weight Quick decrease in body weight Slow decrease in body weight Increase in body weight
Increase in body weight
In which compartment is the largest amount of body fluid stored? Blood plasma Interstitial fluid Extracellular fluid Intracellular fluid
Intracellular fluid
Why do some athletes ingest glycerol prior to exercise? It repels water and acts as a mild diuretic. It attracts water and results in fluid retention. It is a readily available source of glucose during exercise. It directly offsets the rise in body temperature that occurs during exercise.
It attracts water and results in fluid retention.
What is insensible water loss? Loss of water as a result of sweating but not cooling in humid conditions Large losses of water due to excessive sweating Loss of water from the body that is not noticeable Excessive loss of water through urine
Loss of water from the body that is not noticeable
Athletes participating in which sport need to be the most concerned about consuming fluids that contain sodium to offset the amount being lost in sweat? Sprint running Field events (e.g., shot putting, high jumping) 10 km running Marathon running
Marathon running
What is the primary cation in extracellular fluid? Sodium Potassium Calcium Chloride
Sodium
Which accounts for the largest amount of water loss in an athlete exercising in the heat? Feces Lungs Perspiration Urine
Perspiration
_____ is the primary cation in intracellular fluid. Sodium Potassium Calcium Chloride
Potassium
If the osmolarity of intracellular fluid (ICF) is higher than that of extracellular fluid (ECF), what is the tonicity of the blood? The blood is isotonic to the ICF. The blood is hypotonic to the ICF. The blood is hypertonic to the ICF. The blood is hypertonic to the ECF.
The blood is hypotonic to the ICF.
Which of the following is a true statement regarding extracellular (ECF) and intracellular (ICF) fluids under normal conditions? The total concentrations of all solutes of the ECF and the ICF are the same. The ionic composition of the ECF and the ICF are the same. The osmolarity of the ECF is greater than that of the ICF. The osmolarity of the ICF is greater than that of the ECF.
The total concentrations of all solutes of the ECF and the ICF are the same.
Which of the following is a true statement regarding sweat in trained athletes? They typically have lower sweat rates than sedentary individuals. They typically have higher sweat rates than sedentary individuals. They typically start sweating later than sedentary individuals. They seldom differ in sweating between healthy, sedentary individuals.
They typically have higher sweat rates than sedentary individuals.
A decrease in plasma volume occurs within the first few minutes after exercise begins. True False
True
A moderate potassium deficiency can result in increased blood pressure and increased urinary calcium excretion. True False
True
A simple and practical hydration assessment tool to monitor hydration status is to evaluate daily weight loss, urine color, and thirst. True False
True
All fluids can have a diuretic effect. True False
True
Exertional heat cramps may be the result of rapid and large losses of fluid and sodium. True False
True
Glycerol is an osmotically active, water-retaining molecule. True False
True
Glycerol loading results in a gain in body weight. True False
True
Hyponatremia is defined as a plasma sodium concentration below 135 mmol/L. True False
True
It is easy for athletes who train in the heat to dehydrate because the rate of water absorption from the stomach and intestine is usually slower than the rate of loss from sweat. True False
True
It is unsafe to make a blanket recommendation for fluid intake during exercise for all members of the same team. True False
True
Plasma and interstitial fluid, have nearly identical composition and distribution of electrolytes. True False
True
Plasma serves as the fluid transportation medium to transport substances such as red blood cells, gases, and nutrients, throughout the body. True False
True
Under normal conditions, sodium is actively pumped out of cells while potassium is simultaneously pumped into cells. True False
True
When conditions are more humid, sweating is a less effective means of regulating body temperature. True False
True
When hypohydration occurs in the ECF, the osmolarity of the ECF increases and water shifts from the cells to the ECF. True False
True
When the extracellular fluid is hypertonic to the intracellular fluid, there will be a net water movement out of the cell. True False
True
Assuming that it can be tolerated, which athlete may find a beverage containing a carbohydrate concentration greater than 10% to be beneficial during exercise? 800 m runner 10,000 m (10 K) runner Ultraendurance runner A team sport athlete
Ultraendurance runner
Which of the following is a true statement regarding sodium excretion? Urinary sodium excretion is precisely controlled by the kidneys. If sodium intake is high, most of the excess sodium is excreted via sweat. If sodium intake is high, most of the excess sodium is excreted via the feces. Excess sodium intake is difficult to excrete and any excess is stored in the liver.
Urinary sodium excretion is precisely controlled by the kidneys.
Which accounts for the largest amount of water loss in a sedentary individual? Feces Lungs Perspiration Urine
Urine
If the osmolarity of intracellular fluid is higher than that of extracellular fluid, what is the effect on water movement? Water will flow out of the cell. Water will flow into the cell. More water will be absorbed from food. More sweat will be produced.
Water will flow into the cell.
When environmental conditions are more humid, sweating is ____. a more effective means of regulating body temperature a less effective means of regulating body temperature not affected by the change dangerous to an active individual
a less effective means of regulating body temperature
In addition to beverages and food, another source of water for the body is ____. aerobic metabolism anaerobic metabolism osmosis hydrostatic pressure
aerobic metabolism
When an athlete is hypohydrated, ____. core temperature during exercise is lower than when euhydrated blood volume is lower than when euhydrated endurance exercise performance is higher than when euhydrated the amount of water present easily meets the amount required for physiological functions
blood volume is lower than when euhydrated
The immediate feeling of "energy" produced by energy drinks is most likely due to ____. kilocalories carbohydrate caffeine electrolytes
caffeine
To avoid a moderate potassium deficiency, it is recommended that individuals, including athletes, should ____. use a salt substitute (potassium chloride) daily avoid exercising in the heat consume a variety of fruits and vegetables daily consume snack foods such as popcorn
consume a variety of fruits and vegetables daily
The cardiovascular system adjusts to the demands of exercise and oxygen delivery resulting in ____. fluid being transferred from interstitial space into the plasma fluid being transferred from the plasma to the interstitial space water leaking out of the ECF water leaking into the ECF
fluid being transferred from the plasma to the interstitial space
A beverage containing a carbohydrate concentration greater than 10% may be detrimental to an athlete during exercise because ____. gastric emptying is slowed gastric emptying is accelerated volume of urine is increased concentration of urine is increased
gastric emptying is slowed
The Dietary Reference Intake (DRI) for sodium is 1,500 mg daily, however, these recommendations do NOT apply to ____. men and women under the age of 50 sedentary individuals lightly active individuals highly active individuals who sweat heavily
highly active individuals who sweat heavily
Created when there is a difference in fluid pressure between to areas.
hydrostatic pressure
Results in water moving from blood plasma to interstitial spaces.
hydrostatic pressure
Approximately how much sweat can an athlete lose each hour when exercising in a hot and humid environment? 1 milliliter per hour 1 liter per hour 1 gallon per hour 25 cups per hour
hypertonic
Body fluids are considered to be ____ if they have a concentration of solutes that is greater than the concentration of solutes in the cell.
hypertonic
When a person sweats heavily, there is a loss of water from the extracellular fluid and the ECF becomes ____ in relation to the intracellular fluid.
hypertonic
A condition that results from consuming excess fluids is called ____. hypohydration euhydration hyperhydration dehydration
hypohydration
Body fluids are considered to be ____ if they have a concentration of solutes that is less than the concentration of solutes in the cell.
hypotonic
When a fluid has a lower osmolarity than the reference fluid.
hypotonic
The major component of extracellular fluid is ____. blood plasma interstitial fluid lymphatic fluid transcellular fluid
interstitial fluid
Heat cramps (total body cramping when exercising in the heat) in athletes who are "salty sweaters" appear to be caused by ____. dehydration sodium depletion large losses of fluid and sodium non-nutritional factors
large losses of fluid and sodium
Two factors that may be associated with hyponatremia are ____. large losses of sodium in sweat and low water intake large losses of sodium in sweat and excessive water intake intake of salt tablets and low water intake intake of salt tablets and excessive water intake
large losses of sodium in sweat and excessive water intake
Adding small amounts of sodium to a beverage is advantageous because it ____. makes the drink more palatable decreases voluntary fluid consumption inhibits thirst decreases body water retention
makes the drink more palatable
Scientific studies of exercise-associated muscle cramping (EAMC) have concluded that this condition is ____. almost always a result of dehydration almost always a result of electrolyte imbalance almost always a result of a combination of dehydration and electrolyte imbalance not typically a result of dehydration or electrolyte imbalance
not typically a result of dehydration or electrolyte imbalance
One liter of water weighs approximately ____. one pound one kilogram two pounds two kilograms
one kilogram
Concentration of solutes in a particular fluid.
osmolarity
The movement of fluid occurs as a result of controlling the amount of water in the ECF and the ____ of the ECF.
osmolarity
When the number of solutes is measured per liter of solvent.
osmolarity
Water movement from areas of low solute concentration to areas of higher solute concentration.
osmosis
The two best strategies to aid performance and prevent hyponatremia in ultraendurance athletes are ____. replenishment of sodium and prevention of overdrinking replenishment of sodium and voluntary dehydration replenishment of sodium and intake of a large amount of potassium intake of salt tablets and excessive water intake
replenishment of sodium and prevention of overdrinking
Wearing uniforms and protective gear while exercising in the heat typically ____. keeps the sun off the skin and prevents body temperature from rising restricts the evaporation of sweat and results in body temperature rising has little effect on body temperature reduces fluid loss through sweat
restricts the evaporation of sweat and results in body temperature rising
The compound present in the largest amount in sweat is ____. ammonia sodium calcium lactate
sodium
When comparing urine to a color chart, it is recommended that athletes use urine obtained from ____. the first void (urination) of the day the second void (urination) of the day the last void (urination) before going to bed for the night any void (urination) during the day
the first void (urination) of the day
The current American College of Sports Medicine recommendation for fluid intake during exercise is ____. 50-150 ml every 15 to 20 minutes 5-10 ml/kg each hour to drink as frequently and as much as possible to develop a customized fluid plan that considers sweat rate
to develop a customized fluid plan that considers sweat rate
The term voluntary dehydration refers to athletes engaged in exercise who are ____. assigned to the control group in research studies examining fluid intake not within five pounds of their pre-exercise weight testing the precision of their thirst mechanism unable or unwilling to consume sufficient fluid to offset fluid loss
unable or unwilling to consume sufficient fluid to offset fluid loss
The term voluntary dehydration refers to athletes engaged in exercise who are ____. assigned to the control group in research studies examining fluid intake not within five pounds of their pre-exercise weight testing the precision of their thirst mechanism unable or unwilling to consume sufficient fluid to offset fluid loss
unable or unwilling to consume sufficient fluid to offset fluid loss
The least accurate but most practical method of monitoring hydration status in athletes is ____. 24-hour urine volume urine color plasma osmolarity isotope dilution
urine color