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