Bioenergetics and Exercise Metabolism - Part 1 Flashcards
What two factors does O2 extraction depend upon?
- O2 content of blood
2. Uptake rate (removal from blood) by tissues
Name the 6 things that were discussed in lecture that will influence O2 removal rate.
- Capillary density
- Myoglobin content
- Mitochondria number (volume)
- Oxidative capacity of mitochondria
- Muscle fiber type
- PO2 gradient from capillaries to tissue
How does the Bohr Effect influence O2 removal?
When blood has a low pH (acidic) then the oxyhemoglobin dissociation curve moves down and to the right - meaning it is easier to deliver O2 and therefore enhancing removal.
When the temperature increases (heat) the curve shifts down and to the right as well, also helping speed up O2 uptake at the muscles.
Why do we do incremental exercise when looking at VO2??
It allows you to accommodate with each increase until you reach plateau
What are the two physiological factors that influence VO2 max? And what systems do they use?
DELIVERY of oxygen to working muscles –> cardiorespiratory system
UTILIZATION of oxygen by working muscles –> metabolic system (aerobic)
What does it mean for oxygen utilization when a VO2 plateau has been reached?
no more oxygen can be used
***** This doesn’t mean you stop using O2!!! It just means that NO MORE can be additionally utilized
____ is the volume of oxygen consumed and the ability of the body to deliver and use it.
VO2
Oxygen uptake increases _____ until VO2 is reached. How do you know that VO2 is reached with regard to workload?
linearly; there is no further increase in VO2 with increasing work rate
What does an increase in oxygen consumption do for us during exercise?
Allows us to continue to produce the energy needed to contract muscle to meet the demands we are asking of them
What is the primary central factor for controlling VO2?
cardiac output
What are the two divisions of factors that influence O2 consumption during exercise?
central and peripheral
What are the central factors that influence O2 consumption during exercise?
Cardiac Output
- heart rate
- stroke volume (main one that adapts)
When looking at central factors, how does training influence cardiac output?
training increases max stroke volume but doesn’t influence max heart rate (your heart is able to contract harder)
What are the peripheral factors that influence O2 consumption during exercise?
Extraction by tissues (a-vO2)
-oxygen carrying capacity and ability for cells to take O2
What is the difference between central and peripheral factors?
Central factors have more to do with delivery and the cardiorespiratory system while peripheral factors are more looking at what is happening locally at the tissues
How does training affect peripheral factors influencing oxygen consumption during exercise?
- increases capillary density
- increases mitochondrial number (volume)
- increases hemoglobin and myoglobin
Why is it good to increase the number of Hb and Mb?
O2 that is bound to them doesn’t exert a partial pressure
What types of training influence peripheral and central factors?
Peripheral - high intensity interval training
Central - long distance, prolonged exercise
“chemical reactions - pathways that result in synthesis or breakdown of molecules”
metabolism
“the metabolic processes involved in converting food sources into biologically usable energy”
bioenergetics
While we exercise, what respiratory changes do we need to see happen so that we can get enough ATP?
Increased ventilation - rate and depth of breathing
While we exercise, what cardiovascular changes do we need to see happen so that we can get enough ATP? (3)
Increased Q:
- increased HR
- increased SV
- vasodilation to working muscles
While we exercise, what muscular changes do we need to see happen so that we can get enough ATP? (3)
- increase Ca++ release/uptake by SR
- increased myoglobin shuttling
- increase in rate of Energy System pathway
