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