Exercise & Thermal Stress

Question 1

What is the main control center for temperature regulation?

Answer 1

Hypothalamus

Question 2

What happens to superficial arterial and venous blood vessels in the heat?

Answer 2

They dilate to divert warm blood to the body shell.

Question 3

What represents the most important factor in determining the effectiveness of evaporative heat loss?

Answer 3

Relative humidity

Question 4

What happens to heart rate and stroke volume during submaximal exercise?

Answer 4

Heart rate increases; stroke volume decreases; cardio output decreases

Question 5

What takes precedence during physical activity in the heat: circulatory regulation and muscle blood flow or temperature regulation?

Answer 5

Circulatory regulation and muscle blood flow

Question 6

What two competitive cardiovascular demands does the body encounter when exercising in the heat?

Answer 6

-Demand muscles requrie delivery of arterial blood flow to sustain energy metabolism
-Demand arterial blood diverst to the periphery to transport metabolic heat for cooling at the skin’s surface.

Question 7

How much water should you drink pre-activity?

Answer 7

17-20 oz 2-3 hours before the activity
7-10 oz 10 to 15 minutes before activity

Question 8

How much water should you drink every hour while exercising?

Answer 8

7-10 oz every 10-15 minutes, or 28-40 oz every hour

Question 9

Fluid loss coincides with the following five factors.

Answer 9

-Decreased plasma volume
-Decreased stroke volume
-Increased heart rate
-Reduced skin blood flow for a given core temperature
-General deterioration in circulatory and thermoregulatory efficiency

Question 10

What provides the biggest defense against overheating?

Answer 10

Evaporation

Question 11

As ambient temperature increases, what happens to the effectiveness of conduction, convection, and radiation to facilitate body heat loss?

Answer 11

Decreases