Exercise Physiology: Muscle, Fuels and Fatigue Flashcards
Which muscle type is slow twitch?
type I
Which muscle type has more mitochondria?
type I
Which muscle type has the highest capillary density?
type I
What percentage of muscle is type I?
50%
How does training alter muscle fibre types?
endurance training turns type II fibres into type I fibres
What happens in resistance training?
increase in strength quickly because of neuromuscular changes and then over time a more gradual muscle hypertrophy
What transcription factor is activated in bed rest?
Foxo - leads to protein degradation and muscle atrophy
What are the mitochondrial adaptations to exercise?
increased mitochondrial density, increased oxidative enzymes, reduced lactate production, increased fat oxidation, improved insulin action
What is the role of creatine phosphate?
donates a phosphate to ADP to make ATP anaerobically
What is the power and capacity of creatine phosphate?
high power, low capacity
What is the power and capacity of glycolysis?
high power, low capacity
What is the power and capacity of carbohydrate oxidation?
medium power, medium capacity
What is the power and capacity of FFA oxidation?
low power, high capacity
What fuels are used for sprinting?
ATP, creatine phosphate and glycolysis (glycogen to lactate)
What fuels are used for endurance exercise?
carbohydrate and fat
What factors influence exercise metabolism?
exercise intensity and duration, diet, training, environmental temperature, age, gender
What is fatigue?
the inability to maintain the required or expected force or power output - reversed by rest
How can drugs like caffeine increase performance?
by reducing the conscious perception of muscle fatigue
What causes skeletal muscle fatigue?
ROS, metabolic byproducts, inorganic phosphate, ADP, acidosis, electrolyte imbalances - all of these will effect contraction of the muscle
How does carbohydrate ingestion improve exercise capacity?
the more glycogen you have the longer you can exercise before fatigue
Why do you fatigue?
protective against hyperthermia and death
