Lecture 17 Flashcards
What are the factors that cause fatigue?
Central Fatigue
Substrate Depletion
Metabolite Accumulation
Electrolyte Disturbances
Dehydration
Hyperthermia
Muscle microtrauma
Why is training different for marathon runners and sprinters?
Factors limiting sprint and endurance performance differ and require different training types.
What are the 2 measures of endurance performance?
VO2 max and lactate threshold are measures of endurance performance potential.
What are the factors that influence sports performance?
Physiological
Nutritional
Environmental
Biomechanical
Psychological
How does feedback from the muscles affect performance?
When feedback from muscle is eliminated the brain drives the muscle to a greater extent which causes more rapid fatigue. This means the feedback decreases performance but allows weaker performance to last longer.
What are the essentials for sprint success?
Muscle mass to generate force and power
Fast twitch fibres
Neuromuscular recruitment
Fatigue resistance
Ability to generate and tolerate lactic acid
Fast reaction time
When is Phosphocreatine utilized during exercise?
PCr is important in initial stage of exercise.
How does glycogen affect onset of fatigue?
Low glycogen levels makes fatigue set in quicker than high glycogen levels.
How does pH affect fatigue?
Decrease in muscle pH is associated with fatigue.
How does induced alkalosis affect performance?
Induced alkalosis has improved performance
What are the essentials for endurance success?
High VO2 max
Ability to maintain high % of VO2 max
High power output at lactate threshold (high muscle oxidative capacity)
Fatigue resistance
Efficient technique
Ability to oxidise fat at high power outputs (limited carbohydrate stores can be used for longer)
What is a more important determinant of endurance exercise performance; muscle oxidative capacity or VO2 max?
Muscle oxidative capacity is more important in endurance performance compared to VO2 max.
What does lactate threshold tell us about an athlete?
Lactate threshold gives the oxidative capacity.
How does a higher lactate threshold cause endurance athletes to fatigue later?
Higher lactate threshold means oxidation of glycogen takes place which means more fat oxidation takes place preserving glycogen stores and increasing the time to fatigue. (fatigue here is caused by substrate depletion)
How does intramuscular glycogen affect performance and how can this glycogen be increased?
Intramuscular glycogen increase causes longer lasting endurance. Intramuscular glycogen can be increased via CHO loading.
