L12;C5 Flashcards
With respect to fatigue, two main factors influence it. What are they?
Decrements—> with continual effort, decrements of fatigue are accompanied by sensation of tiredness
Inability—> inability to maintain required power output to continue muscular work at a given intensity
What is fatigue reversible with?
Rest
What are the four major causes of fatigue?
- Inadequate energy
- Accumulation of metabolic by products and chemical reactions that provide energy transfer
- Failure of muscle contractile mechanism
- Altered neural control of muscle contraction
PCr depletion coincides with what? Why does this occur?
Coincides with fatigue and is used with short term exercise, PCr depletes more quickly and total ATP does
What helps defer PCr depletion? Why?
Pacing, since pi may be caused for fatigue
What is the relationship between glycogen storage and exercise?
As exercise increases, glycogen storage decreases. It will decrease early on. depletion of glycogen has been linked to low exercise
Fibres that are recruited first are most likely to do what first?
Decrease first
Muscle glycogen is insufficient for what kind of exercise?
Prolonged exercise
As muscle glycogen ______ glycogenolysis ______
Decreases, increases
What will muscle glycogen uses vary upon? Give an example?
The type muscle group. For example, at 2 hours at 70% VO2 max gastric uses most glycogen while running.
What limits glycogenolysis?
- NADH production in kreb cycle
- ETC activity
- No glycogen= inhibited substrate oxidation
What are some metabolic by products of fatigue?
- Pi from breakdown fo PCr
- heat retained by body
- lactic acid
- H+ lactic acid—> lactate H+
What happens when heat alters metabolic rate?
- increase in rate of carb utilization
- faster glycogen depletion
- high muscle temp may impaired muscle function
What is the highest temp we can go at 70% max VO2?
11 degrees
Why does muscle PH decrease during a sprint and increase at recovery?
Due to the lactic acid by products, Pi decreases pH and more H+ ions in blood slightly