Causes of Fatigue

Question 1

What are the three acceptable causes of fatigue?

Answer 1

• Depletion of Fuel
• Accumulation of metabolic by-products
• Elevated Core Body Temperature

Question 2

Which two fuels are reffered to for depletion of fuels?

Answer 2

• PC Stores
• Glycogen Stores

Question 3

After how long do PC stores deplete, and which system does it affect?

Answer 3

After approximately 10 seconds of high intensity exercise. Affects ATP-PC energy system.

Question 4

After how long do Glycogen stores deplete, and which system does it affect?

Answer 4

After approximately 90 minutes of high intensity activity.

Question 5

Which energy system does glycogen depletion affect.

Answer 5

Aerobic Glycolysis Energy System

Question 6

After glycogen depletion, aerobic energy system relies on which fuel for energy?

Answer 6

Triglycerides

Question 7

Why does an athlete’s intensity drop when they hit the wall?

Answer 7

• They deplete their glycogen stores, and rely on their triglyceride stores
• Triglycerides require more oxygen for breakdown
• Triglyceride breakdown is a complex reaction
• Therefore, rate of ATP synthesis is slower, leading to decrease in intensity.

Question 8

What is an important metabolic bi-product?

Answer 8

Accumulation of Hydrogen Ions

Question 9

What system causes accumulation of Hydrogen Ions?

Answer 9

Anaerobic Glycolysis System

Question 10

What does accumulation of Hydrogen Ions cause?

Answer 10

• Decrease in muscle pH levels
• Increase in muscle acidosis
• Inhibits enzyme activity
• Decreases rate of ATP resynthesis, results in lower intensity

Question 11

What is a by-product of the Aerobic ATP resynthesis?

Answer 11

Heat Energy

Question 12

What is the body’s core body temperature?

Answer 12

37 degrees C

Question 13

What is the name of the process when body regulates rise in core body temperature?

Answer 13

Thermoregulation

Question 14

What is Vasodilation and Vasoconstriction?

Answer 14

• Vasodilation - Expansion of blood vessels
• Vasoconstriction - Constriction of blood vessels

Question 15

What is Stroke Volume?

Answer 15

The amount of blood the heart can pump out in a single beat

Question 16

What is blood viscosity?

Answer 16

The thickening of blood and it’s resistance to flowing.

Question 17

Explain in simple dot-points the steps involved in thermoregulation

Answer 17

• Redistribution of blood flow
• Sweating
• Reduction in stroke volume due to viscosity

Each dot-point will have it’s own flashacrd later

Question 18

Explain the redistribution of blood flow in body in terms of Elevated Core Body Temperature

Answer 18

• Blood is redistributed away from muscles and to the skin
• Blood vessels vasoconstrict to muscles and vasoldilate to skin
• Means less blood going to muscles will result in less oxygen, leading to lower intensity

Question 19

Explain sweating in terms of Elevated Core Body Temperature

Answer 19

• Blood taken to skin’s surface will cause sweating
• Sweat will be produced mainly by water from blood plasma
• Decrease in water levels in blood will increase viscosity
• Evaporation of sweat on skin will enable cooling

Question 20

Explain reduction of stroke volume due to blood viscosity in terms of Elevated Core Body Temperature

Answer 20

• Due to increased viscosity of blood, it is harder for heart to pump blood
• Therefore stroke volume will lower
• This will result in less blood being pumped = less oxygen reaching muscles = lowering intensity

Question 21

What does multifactorial causes of fatigue mean?

Answer 21

Many causes of fatigue