Ch 13
The ultimate goal of heat acclimation is to reduce code temperature during exercise. (T/F)
...true
The ability of the hypothalamus to regulate body temperature is compromised when core temperature falls below
34.5 C (94.1 F)
Exercise induced asthma in the cold affects as many as
50% of winter athletes
Acclimation is best achieved through
Exercising at low-to moderate intensity in the heat for 1h/day for 9 to 14 days
Although the majority of ATP breakdown contributes to cellular work, approximately 25% of it contributes to metabolic heat production. (T/F)
False
Frost bitten tissue should be rapidly rewarmed as quickly as possible. (T/F)
False
Higher circulating catecholamines during cold exposure contribute to higher FFA oxidation. (T/F)
False
Meteorological heat index and environmental WBGT values provide identical information. (T/F)
False
When C, K, E, and R are considered together, heat transfer occurs
Four times faster in water than in air
During exercise in the cold, the primary metabolic substrate is
Glucose/glycogen due to increased circulating catecholamines
If core temperature is not excessively high but an athlete is still exhibiting dizziness, nausea or vomiting; and a rapid weak pulse, he or she is most likely suffering from
Heat exhaustion
______ is most effectively treated using whole-body immersion in an ice bath.
Heatstroke
Increased plasma volume with heat acclimation leads to
Increased cardiac output and skin blood flow
Which of the following equations represents total gain by the body?
M-W+R+C+K-E > 0
Frostbite should be rewarmed
Preferably in a hospital
Heat that the body gains from the sun on a cloudless day would be categorized as
Radiation
Heat cramps must be treated with
Rapid sodium replenishment
When sweat glands become more sensitive to aldosterone after acclimation, they
Reduce sweat sodium content
A good way to minimize the chance of hyperthermia is to
Schedule early morning and evening practices
As air temperature reaches skin temperature , convection becomes an avenue of heat gain. (T/F)
True
Sweating and skin vasodilation are the body's only physiological heat loss mechanisms. (T/F)
True
Swimming in 12 degrees Celsius water is more dangerous than running in 12 C air. (T/F)
True
Which of the following variables is most important in determining whether hot environmental conditions are safe for competition?
Wet bulb temp
Which of these is not an effector controlled by the POAH?
Apocrine sweat glands
Sweat glands functionally resemble which organ(s) in the body?
Brain
Heat that the body gains from sitting on hot turf would be categorized as
Conduction
As windchill becomes greater, _______
Connective heat loss increases
During exercise in the cold, muscle
Contractile force decreases
Of the four major heat transfer variables, which one is the most important for daily living?
Convection
When an athlete is exercising in hot and humid weather
Core temperature will increase faster
Endurance training causes sweat glands to
Decreases electrolyte content of sweat secretion
Which of these hormones does not help control fluid balance during exercise?
Epinephrine
The primary source of heat loss during exercise in the heat is
Evaporation
The critical temperature theory suggest that
Exercise is shut down when a given core temperature is reached
Which of these is a response to a single bout of exercise in the heat?
Increased vasodilation of skin arterioles
Whose body morphology will lead to the most heat loss at a given cold temperature?
Slender child
In the heat, clothing functions as all of these except
Source of radiation
If muscle glycogen and blood glucose both start to run low during exercise in the cold, what is the consequence?
Suppression of shivering
When athletes train in the heat, they are undergoing acclimatization. (T/F)
True
Which of these occurs during cardiovascular drift?
Upward drift in heart rate