Muscular fatigue and nutritional + hydration strategies Flashcards
(21 cards)
What is a common cause of fatigue during exercise?
Fuel depletion, such as the depletion of creatine phosphate or glycogen, is a common cause.
Where is creatine phosphate (CP) stored and how long does it last?
CP is stored in fast-twitch muscle fibres and lasts about 8–10 seconds during high-intensity activity.
What affects how much CP a muscle can store?
Muscle size affects CP storage — larger muscles store more CP. Resistance training can also increase CP storage.
What is the rate and capacity of the ATP-CP system?
It has the fastest rate of ATP resynthesis but a limited capacity (finite supply).
What happens when CP depletes?
The anaerobic glycolysis system increases its contribution, but ATP resynthesis slows and power output decreases.
What causes faster CP depletion during exercise?
A faster rate of energy demand leads to faster CP depletion and greater usage.
What happens when more CP is depleted and more ATP is produced?
It takes longer to restore CP levels back to pre-exercise levels.
What type of recovery is needed to replenish CP stores?
Passive recovery is needed to restore CP effectively.
How long can glycogen stores sustain moderate to high-intensity activity?
Around 1.5 to 2 hours.
What happens when glycogen stores are depleted and fats become the main fuel source?
The rate of ATP production significantly decreases, reducing power output.
Where are carbohydrates (CHO) stored in the body?
Mostly as glycogen in the muscles and liver, with small amounts as glucose in the blood.
How does exercise intensity affect glycogen depletion?
Higher intensity causes faster glycogen depletion and an earlier switch to fats as the main fuel.
How can athletes increase glycogen stores before competition?
Through carbohydrate loading and other dietary strategies.
What strategy can delay the use of fats as the primary fuel during an event?
Consuming carbohydrate-rich gels during activity.
What is Pi and how is it produced during exercise?
Pi (inorganic phosphate) is a by-product of ATP and CP breakdown during high-intensity activity.
How does Pi accumulation contribute to fatigue?
It interferes with muscle contractions, causing slower contraction frequency, reduced force, and lower power output.
What are metabolic by-products?
Waste products from the breakdown of chemical or food fuels in the body, such as Pi and H+.
What is formed when glycogen is broken down without oxygen during anaerobic glycolysis?
Lactic acid
What happens to lactic acid after it’s produced?
It breaks down into lactate and H⁺ ions.
What causes muscles to become acidic during high-intensity exercise?
The accumulation of H⁺ ions when intensity exceeds the lactate inflection point (LIP).
How do H⁺ ions impact performance?
They slow contraction frequency, reduce force production, and lower power output by inhibiting glycogen breakdown.
