Acute Metabolic Responses To Exercise Flashcards
What main factors determine energy pathway utilisation
Exercise intensity
Exercise duration
What energy system predominantly supports intense, maximal exercise
Substrate level phosphorylation (PCr, glycolysis leading to lactate production)
As sprint duration continues, what changes in the contribution of energy systems
The contribution of substrate-level phosphorylation declines and oxidative phosphorylation increases in contribution at the cost of the total power that can be generated
How can maximal power be restored
Restoration of maximal power requires recovery of the capacity to maximally utilise substrate phosphorylation pathways
What supports ATP supply for prolonged exercise
Carbohydrate and fat oxidation
What is a critical regulator of muscle contraction
Calcium
What does disrupted handling of calcium cause
Fatigue
What causes lactate production
When ATP demand is too high for the pyruvate to enter the mitochondria
What are the key enzymes in substrate level phosphorylation
Creatine kinase, phosphorylase, phosphofructokinase, lactate dehydrogenase
Why does fat oxidation decrease at higher intensities
- Decreased plasma FA availability
- Decreased IMTG lipolysis
-Decreased mitochondrial fat uptake
What does endurance exercise rely on
Mobilisation of fuels from outside (plasma fatty acids, blood glucose) and inside (IMTG, glycogen) the muscle
What control is mobilisation of fuels under
Hormonal control in addition to signals related to energy status and muscle contraction within the muscle itself
Which fuel type will be used to a greater extent during endurance exercise after a long period of endurance training
Lipid / fat
What biomarkers are used to estimate mitochondrial content
Citrate synthase
Complex I (NAHD: ubiquinone oxidoreductase)
Complex II (succinate dehydrogenase)
Complex III (cytochrome c oxidoreductase)
Complex IV (cytochrome c oxidase)
Complex V (mito-AMP synthase)
Any mitochondrial proteins
