Chapter 23: Exercise and the Environment

Besides carbon monoxide and sulfur dioxide, which of the following gases is classified as a major pollutant by the Clean Air Act?

Ground-level ozone

Which of the following people is most likely to be suffering from increased exposure to carbon monoxide?

Harry, who is a chain smoker

_____ is a sensitive indicator of dehydration, environmental heat load, and acclimation and should be measured several times during exercise

Heart rate

_____ is the best protection against exercise-related heatstroke and heat exhaustion

Heat acclimation

_____ is a heat-related medical emergency that can lead to death

Heatstroke

____ is caused when heat loss from the body exceeds heat production

Hypothermia

Why do mountain climbers lose weight when climbing high altitudes?

Hypoxia suppresses hunger and food intake

The insulation quality of clothing is given in ____ units

clo

Which of the following reflexes increases oxygen consumption to 1000 ml/min?

shivering

The magnitude of the VO2 max response at altitude is greater in those who suffer _____

some desaturation at sea level

People who successfully deal with altitude have _____

strong hypoxic ventilatory drives

Match the temperatures of severe hypothermia (in the left column) with their effects (in the right column)

28C --> ventricular fibrillation 26C --> no response to pain 24C --> hypotension 19 --> EEG silence

Hypothermia is defined clinically as a core temperature below _____

35°C (95°F)

Identify the reasons for the rapid decrease of maximal oxygen uptake at high altitudes. (Check all that apply.)

-The desaturation of hemoglobin -The decrease in maximal cardiac output

Identify the environmental factors associated with hypothermia. (Check all that apply.)

-Water vapor pressure -temperature

Arrange the stages of heat injury in the order of their occurrence. (Place the first stage at the top.)

1. exercise induced muscle cramps 2. heat syncope 3. heat exhaustion 4. exertional heatstroke

The body temperature that could prove fatal to humans is _____

45 degree Celsius

At sea level, hemoglobin is about 96% to 98% saturated with oxygen. At an altitude of 2300 meters and 4000 meters, saturation falls to 88% and _____, respectively.

71%

Identify the most likely reason for the decrease in maximal oxygen uptake with increase in altitude

A decrease in cardiac output

Gerald has mild hypothermia and is taken to a hospital. Identify a treatment procedure to be followed after Gerald is moved to a warm environment.

Apply heat to the trunk and other areas of heat transfer

Which of the following is proportional to work rate?

Core temperature

What is the first thing to do when dealing with a person suffering from severe hypothermia?

Determine if CPR is necessary

Which of the following is a source of submicroscopic particulate matters?

Diesel engine vehicles

Match the types of temperature measurement (in the left column) with their descriptions (in the right column)

Dry bulb temperature --> Measurement of air temperature taken in the shade Black globe temperature --> Measurement of the radiant heat load taken in direct sunlight Wet bulb temperature --> Measurement of air temperature with a thermometer whose mercury bulb has a covering of damp cotton wick

Identify a safety precaution that should be taken to avoid heat-related illness while training for a sport

Emphasize preseason conditioning to promote acclimation

Identify a recommendation for protection against heat illness for individuals who exercise for fitness

Expose as much skin as possible during exercise

What kind of fabrics increases the risk of heat injury?

Fabrics impermeable to water

What kind of clothing should be worn to ensure against heat injury?

Fabrics that will wick sweat to the surface for evaporation

Identify a true statement about atmospheric pressure

It decreases with increasing altitude

Identify a true statement about the effect of sulfur dioxide on health

It does not affect lung function in normal subjects

Identify an effect of ozone on exercise

It is directly proportional to a decrease in pulmonary function following activity

Identify a true statement about the functional role of subcutaneous fat thickness in an individual

It plays a role in the onset and magnitude of the shivering response to cold exposure

Which of the following is equal to the product of maximal cardiac output and the maximal arteriovenous oxygen difference?

Maximal oxygen uptake

Identify an intrinsic factor that adds to the overall heat load of the body during exercise

Metabolic rate

Identify the condition that triggers the lowering of the heart rate and the oxygen demand of the heart muscle

Myocardial hypoxia

Short-term anaerobic performance is not affected by the low PO2 at altitude because _____

O2 transport to the muscles is not limiting performance

Identify a true statement about ventilatory response at altitude

Pulmonary ventilation increases with altitude

What precaution should be taken to avoid heat-related illness when organizing a sports event in a city?

Schedule the event in cooler months

Who among the following is most likely to have complete acclimatization at high altitudes?

Stacy, who moved to the mile-high city Denver as a child

Identify a recommendation to decrease the rate of heat loss in long-term immersions

Stay as still as possible

Which of the following is an insulating factor associated with hypothermia?

Subcutaneous fat

Identify the changes in the atmosphere at higher altitudes

The air is less dense

Identify a true statement about the effect of altitude on gas composition and the human body

The percentages of O2, CO2, and N2 are the same at altitude as at sea level

Which of the following is true of water in the context of heat loss?

The thermal conductivity of water is 25 times greater than that of air

Identify a true statement about body temperature responses to cold exposure in individuals aged over 60 years

They are less tolerant to cold exposures

Which of the following is a characteristic of swimmers with high levels of subcutaneous fat?

They are more buoyant

Identify a true statement about fit subjects

They can still develop exercise-related heatstroke

Which of the following is true of children and their body temperature response to cold exposure?

They have large surface area-to-mass ratio

Identify an adverse effect of particulate matter on individuals

They promote pulmonary infection

Identify the temperature range associated with a low risk of both hypothermia and hyperthermia

WBGT 50-65°F (10-18.3°C)

The _____ guide was developed to quantify the overall heat stress associated with any environment

Wet Bulb Globe Temperature

_____ increases the number of cold air molecules coming into contact with the skin so that heat loss is accelerated

Wind

Identify a true statement with respect to wind, exercise, and heat loss

Wind places air molecules into contact with the skin

If maximal stroke volume and maximal heart rate do not change much at high altitudes, then the decrease in VO2 max is due to _____

a difference in oxygen extraction

Prolonged exposures to altitude result in _____

a reduction in plasma volume

The ____ ____ ____ (AQI) is a measure of the quality of the air for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particulate matter (<2.5-μm diameter), carbon monoxide, sulfur dioxide, and nitrogen dioxide

air quality index

Which of the following occurs when a person has mild hypothermia with a core body temperature of 34C?

amnesia

The _____ at any spot on earth is a measure of the weight of a column of air directly over that spot

atmospheric pressure

A depression in maximal heart rate is reversed by the use of _____

atropine

Exposure to sulfur dioxide causes _____ in individuals suffering from asthma

bronchoconstriction

Martin suffers from a decrease in the capacity for oxygen transport. Which of the following pollutants is most likely to be of high concentration in Martin's body?

carbon monoxide

The lower atmospheric PO2 causes a(n) _____

decrease in alveolar partial pressure

Prolonged exposure to only 0.12 parts per million of ozone is enough to _____

decrease lung function

The variability in the decrease in VO2 max across individuals relates to the _____

degree to which athletes experience desaturation of arterial blood during maximal work

High levels of hypoxia inducible factor-1 (HIF-1) in the kidney activate genes that signal the production of a hormone called _____, which stimulates the production of red blood cells in long bones.

erythropoietin

True or false: The number of molecules of O2 per liter of air is reduced at altitude. Therefore, an individual should breathe in much less air to take in the same amount of oxygen at altitude

false The number of molecules of O2 per liter of air is reduced at higher altitudes. Therefore, an individual should breathe in much more air to take in the same amount of oxygen.

True or false: During self-paced exercise in the heat, wind increases physiological strain and reduces performance

false During self-paced exercise in the heat, wind reduces physiological strain and improves performance

True or false: Long-term aerobic performances are unaffected by the lowering of partial pressure at altitudes

false Long-term aerobic performances are clearly affected by the lowering of partial pressure at altitudes

True or false: The changes in atmospheric pressure in high altitude will negatively influence the performance of a sprinter

false Sprint performances are either not affected or are improved in high altitudes

Identify a nutrient that is a primary fuel to support shivering in well-fed individuals

fat

Lee has been living in Tibet at an altitude of 14,000 feet since childhood. His lungs have a high level of nitric oxide, which increases the oxygen saturation of the existing hemoglobin. This indicates that Lee _____

has already acclimatized

Heat-related illness and injury due to elevated body temperature is called _____

hyperthermia

The low PO2 experienced at altitude triggers an almost immediate increase in cellular levels of a stress protein called _____

hypoxia inducible factor-1 (HIF-1)

Heat acclimation by exercising in the heat leads to a(n) _____

increase in plasma volume

Identify a physiological effect experienced by mountain climbers at high altitudes

loss of weight

A high level of fitness in an individual is related to a _____

lower risk of heat injury

Maximal performances in excess of two minutes are primarily dependent on _____

oxygen delivery

The oxygen hemoglobin curve shifts to the left so that hemoglobin is more saturated when the _____

pH is elevated

Oxygen extraction is lower at altitude primarily because of _____

the desaturation of the arterial blood

Clothing provides insulation by _____

trapping air

The ____ ____ ____ indicates what the effective temperature is for any combination of temperature and wind speed

wind chill index