Water Requirements & Fluid Balance Flashcards
Wet bulb globe temperature
Comprehensive index of environmental heat stress
Dehydration
Reduction in body water content
Radiation
Transfer of heat by emission from one object to another
Hypothalamus
The central thermal controller or “thermostat” of the body
Euhydration
Normal state of body water
Reactive oxygen species’s
Can cause damage to cellular membranes making them leaky
Endotoxins
Bacterial toxins from gut that can be released into circulation
Convection
Exchange of heat between a solid object and one that moves
Hyperthermia
Potentially dangerous rise in body temperature
Heat syncope
Loss of consciousness related to heat injury
True or false?
Water accounts for 50% – 60% of total body mass with adipose tissue containing more water by mass then lean body tissues?
False
Water loss occurs through?
4
1) respiration
2) skin – evaporation of sweat
3) feces
4) urine
Water gain occurs through:
3
1) ingestion of fluids
2) ingestion of food
3) metabolic breakdown of macronutrients
_________ generally begins when body temperature reaches 39.5°C (103°F)
Central (Brain) fatigue
List four factors that directly dictate environmental heat stress
A) ambient temperature
B) relative humidity
C) Wind velocity
D) Solar radiation
True or false?
Body heat transferred into a relatively cool bench used to rest on during interval sprints is an example of conduction.
True
High ambient temperature in high humidity = high risk for _________ & ________
Dehydration and hyperthermia
A wetbulb globes temperature (WBGT) is derived from a special device containing multiple thermometers that measures what specific components of heat stress?
A) humidity
B).radiation
C) ambient temperature
The hypothalamus, or thermostat of the body, can stimulate ________ and the initiation of ______ to allow for optimal dissipation of heat
Cutaneous dilation, sweating
List five physiological effects that occurred during dehydration that have an adverse effect on exercise performance
A) reduction of blood volume B) decreased skin blood flow C) decreased heat dissipation D) increased core temperature E) increased rate of muscle glycogen use
True or false?
Reliance on thirst as the signal to drink is not optimal as a degree of hydration sufficient to impair performance can occur before the desire for fluid intake is evident
True
Environmental heat stress is dictated by each of the following except?
A) ambient temperature
B) core radiation
C) relative humidity
D) Wind velocity
B) Core radiation
Which of the following modes of potential heat loss is severely limited when training in a humid environment?
A) radiation
B) conduction
C) convection
D) evaporation
D) evaporation
How much water can a fit Ashley potentially lose each hour in the form of sweat when engaging in strenuous training in the hot environment?
A) 0.5 L/hour
B) 1.0 L/hour
C) 1.5–2.0 L/hour
D) 2.0–3.0 L/hour
D) 2.0–3.0 L/hour
Which of the following is not a physiological adaptation that occurs as an athlete acclimates to training in the heat?
A) blood volume increases
B) in earlier onset of sweating
C) an increase in the number of sweat glands
D) an increase in the capacity for blood flow to the skin
C) an increase in the number of sweat glands
Water loss of 5% of total body weight can decrease the capacity for work by what percentage?
A) 10%
B) 20%
C) 30%
D) 40%
C) 30%
Which of the following issues is related to heat syncope?
A) endotoxemia
B) enhanced heat dissipation
C) Hyperhydration
D) Low electrolytes
A) endotoxemia
Which of the following is not considered a risk factor for heat injury/illness?
A) obesity
B) excessive sleep (>10hrs)
C) Low physical fitness
D) lack of acclimatization
B) excessive sleep (>10hrs)
Which of the following supplements me enhance fluid retention during hyperhydration?
A) caffeine
B) glutamine
C) glycerol
D) lactose
C) glyceryl
Which of the following is not an optimal attribute of fluid consumption during prolonged events (>1hour)
A) The fluid should be cooler than the ambient temperature
B) fluid should be ingested at a rate of 600–1200 ML/hour
C) The fluid should contain sodium
D) The fluid should be hypertonic with respect to blood plasma
D) The fluid should be hypertonic with respect to blood plasma
Which of the following describes the optimal intake of fluids to allow hyperhydration prior to prolonged competitive event in the heat?
The athlete should consume:
A) 1–2 ML of fluid per kilogram of BW about 2 hours prior to the event
B) 3–5 ML of fluid per kilogram of BW about 1 hour prior to the event
C) 6-8 ML of fluid per kilogram of body weight about 2 hours prior to the event
D) 8–10 ML of fluid per kilogram of body weight about 3 hours prior to the event
C) 6-8 ML of fluid per kilogram of body weight about 2 hours prior to the event
Hydration
Relates to the balance between water intake and water loss
