Metabolism for Ergogenic Benefit W3 Flashcards
What does HIIT increase?
The capacity for anaerobic energy production
Enhanced tolerance of metabolic acidosis
Improved ionic regulation (K+ balance)
What does endurance exercise increase?
Increased VO2 max
Enhanced skeletal muscle mitochondrial density
What does resistance training increase?
Increased strength
Increased neuromuscular function
Increased muscle mass
Why is there enhanced tolerance of metabolic acidosis due to HIT?
Increased muscle buffer capacity
What does increased VO2 max allow?
Greater fatigue resistance
What does enhanced skeletal muscle mitochondrial density allow?
Decreased CHO utilisation
Decreased oxidation
Decreased lactate production
Increased fat oxidation
Increased muscle CHO oxidation
What does creatine supplementation do?
Enhances ATP resynthesis
Increase muscle mass and strength
Why does creatine supplementation enhance ATP resynthesis?
There is an increase in PCr availability
What does short-term ingestion of creatine monohydrate do?
Increase total skeletal muscle creatine content by 20-25% and PCr levels by 10-15%
What does carbohydrate loading do prior to exercise?
Increases endurance capacity and performance
Increases muscle glycogen
Why does blood glucose levels decline during prolonged strenuous?
Liver glycogen becomes depleted
Increased liver gluconeogenesis is unable to generate glucose at a rate sufficient to match skeletal muscle glucose uptake
How does CHO supplementation maintain blood glucose levels?
Delays fatigue
Improves muscle energy balance when muscle glycogen levels are decreased
Maintains CHO oxidation
What does glucose ingestion do?
Increased muscle glucose uptake
Decrease liver glucose output
Why may central neural fatigue develop during prolonged exercise?
Hypoglycaemia
Decreased cerebral glucose uptake
When is NH3 (Ammonia) produced?
Produced via within contracting skeletal muscle by the breakdown of ATP and amino acids
What can ammonia affect?
Neurotransmitter levels
Central neural fatigue
What does CHO ingestion attenuate?
Muscle and plasma NH3 accumulation during exercise
What does increased plasma fatty acid availability decrease?
Muscle glycogen utilization
CHO oxidation
What does a high-fat diet do?
Decrease reliance on CHO
What does a high-fat diet induced with ketosis mark?
Decrease in muscle glycogen
Why is the HIT exercise impaired on the high-fat diet?
There is an inability to fully activate glycogenolysis and PDH during exercise
What is nutritional ketosis?
Metabolic state in which the body burns fat and ketones, rather than glucose as its primary fuel
What does Ketosis alter?
Fuel preference
What does caffeine do?
Increases endurance performance
Decreases muscle glycogen usage
Enhances lipolysis and fat oxidation during exercise
What are catecholamines?
Increases lipolysis and fatty acid concentrations during rest periods
What does caffeine increase?
Catecholamines
How are ergogenic effects mediated?
Binding of adenosine receptors in central and peripheral nervous systems
What physical positives does caffeine provide?
Increased self-sustained firing
Increased voluntary activation
Increased in maximal force in central nervous system
Decreases sensations associated with force, pain and perceived exertion or effort during exercise peripheral system
What may high caffeine cause?
Anxiety
Jitters
Insomnia
Inability to focus
Gastrointestinal unrest
Irritability
What role does carnitine have?
Moves fatty acids across the mitochondrial membrane
Regulates number of acetyl-CoA in the mitochondria
What are free carnitine levels like in high-intensity?
Low
Where is nitrate produced from?
L-arginine via action nitric oxide synthase
Where can nitrate be ingested from?
Beetroot juice
How can nitrate be formed?
Nonenzymatic reduction of nitrate and nitrite
What is a major determinant of muscle buffering capacity?
Carnosine content
What happens when ATP, PCr and glycogen are broken down?
Increases:
ADP
Mg2+
ADP
Pi
Lactate
H+
(All increase chance of fatigue)
What does increased H+ concentration interfere with?
Muscle force
Power production
What does ingestion of beta-alanine increase?
Muscle carnosine content
Enhances HIT performance
Who has higher carnosine content?
Anaerobic athletes
What is muscle buffering capacity?
The ability of muscles to neutralise the acid that accumulates in them during them high intensity exercise
What is ROS important roles as signalling molecules mediating the acute and chronic responses to exercise?
Superoxide anions
Hydrogen peroxide
Hydroxyl radicals
What does ROS negatively affect when it is accumulated at higher levels?
Muscle force
Power production
Induce fatigue
What does the ingestion of N-acetylcysteine enhance?
Muscle oxidant capacity
Attenuates muscle fatigue
What is the % of mechanical efficiency?
20%
How does hyperthermia impairs exercise performance?
Effects:
Central neural drive
Cardiovascular function
Muscle metabolism/ function
Fluid loss/ dehydration
Decrease skeletal muscle blood flow
How is muscle glycogenolysis accelerated?
Increased plasma catecholamines
Elevated muscle temperature
How is fatigue prevented?
Acclimation
Pre-exercise cooling
Fluid ingestion
