Muscle Oxidative Function Flashcards
What effect does exercise training have on muscles specifically?
Increase of mitochondrial biogenesis,
Qualitative remodelling type I and IIA fibres,
Increase of muscle oxidative capacity
Define oxidative capacity (mVO2)
A muscles maximal ability to use oxygen
What’s the difference between oxidative capacity and endurance capacity?
Oxidative capacity refers to a MUSCLES ability to use oxygen,
Endurance capacity relates to an INDIVIDUALS oxidative capacity.
What is the oxygen cascade?
The transfer of oxygen from ambient air ->alveolar gas -> arterial blood -> average systemic capillary blood -> mitochondria.
How does oxygen delivery to the tissues work?
By passive transfer of the gas down it’s partial pressure gradient.
Describe the structure of the mitochondria.
Outer membrane,
Inter membrane space,
Inner mitochondrial membrane - where oxidative phosphorylation occurs,
Matrix - contains enzymes and solutes for kerbs and links reaction,
Cristae - folds on matrix to maximise SA,
Ribosomes - protein production
central limiting factors for VO2 max
Pulmonary diffusion capacity,
Cardiac output,
Oxygen carrying capacity of the blood
Peripheral limiting factors for VO2 max
Oxygen extraction,
Mitochondrial respiratory capacity
What may cause a loss of muscle oxidative capacity?
Physical activity,
Ageing,
Chronic disease
What 2 things are key contributors to a decline in aerobic performance in masters?
Loss of muscle mass and a reduction in mitochondrial content
What is the Fick equation?
The relationship between VO2, blood flow and O2 extraction.
VO2 = CO x a-vO2 diff
Name 3 methods of measuring muscle oxidative function
Muscle biopsy,
31P MRS,
NIRS
How does MICT and HIIT training induce changes in oxidative capacity?
By activating intercellular signalling pathways regulating mRNA transcription of genes encoding mitochondrial proteins
