Bioenergetics and Exercise Metabolism - Part 1

Question 1

What two factors does O2 extraction depend upon?

Answer 1

1. O2 content of blood

2. Uptake rate (removal from blood) by tissues

Question 2

Name the 6 things that were discussed in lecture that will influence O2 removal rate.

Answer 2

1. Capillary density
2. Myoglobin content
3. Mitochondria number (volume)
4. Oxidative capacity of mitochondria
5. Muscle fiber type
6. PO2 gradient from capillaries to tissue

Question 3

How does the Bohr Effect influence O2 removal?

Answer 3

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.

Question 4

Why do we do incremental exercise when looking at VO2??

Answer 4

It allows you to accommodate with each increase until you reach plateau

Question 5

What are the two physiological factors that influence VO2 max? And what systems do they use?

Answer 5

DELIVERY of oxygen to working muscles –> cardiorespiratory system

UTILIZATION of oxygen by working muscles –> metabolic system (aerobic)

Question 6

What does it mean for oxygen utilization when a VO2 plateau has been reached?

Answer 6

no more oxygen can be used

***** This doesn’t mean you stop using O2!!! It just means that NO MORE can be additionally utilized

Question 7

____ is the volume of oxygen consumed and the ability of the body to deliver and use it.

Answer 7

VO2

Question 8

Oxygen uptake increases _____ until VO2 is reached. How do you know that VO2 is reached with regard to workload?

Answer 8

linearly; there is no further increase in VO2 with increasing work rate

Question 9

What does an increase in oxygen consumption do for us during exercise?

Answer 9

Allows us to continue to produce the energy needed to contract muscle to meet the demands we are asking of them

Question 10

What is the primary central factor for controlling VO2?

Answer 10

cardiac output

Question 11

What are the two divisions of factors that influence O2 consumption during exercise?

Answer 11

central and peripheral

Question 12

What are the central factors that influence O2 consumption during exercise?

Answer 12

Cardiac Output

• heart rate
• stroke volume (main one that adapts)

Question 13

When looking at central factors, how does training influence cardiac output?

Answer 13

training increases max stroke volume but doesn’t influence max heart rate (your heart is able to contract harder)

Question 14

What are the peripheral factors that influence O2 consumption during exercise?

Answer 14

Extraction by tissues (a-vO2)

-oxygen carrying capacity and ability for cells to take O2

Question 15

What is the difference between central and peripheral factors?

Answer 15

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

Question 16

How does training affect peripheral factors influencing oxygen consumption during exercise?

Answer 16

• increases capillary density
• increases mitochondrial number (volume)
• increases hemoglobin and myoglobin

Question 17

Why is it good to increase the number of Hb and Mb?

Answer 17

O2 that is bound to them doesn’t exert a partial pressure

Question 18

What types of training influence peripheral and central factors?

Answer 18

Peripheral - high intensity interval training

Central - long distance, prolonged exercise

Question 19

“chemical reactions - pathways that result in synthesis or breakdown of molecules”

Answer 19

metabolism

Question 20

“the metabolic processes involved in converting food sources into biologically usable energy”

Answer 20

bioenergetics

Question 21

While we exercise, what respiratory changes do we need to see happen so that we can get enough ATP?

Answer 21

Increased ventilation - rate and depth of breathing

Question 22

While we exercise, what cardiovascular changes do we need to see happen so that we can get enough ATP? (3)

Answer 22

Increased Q:

• increased HR
• increased SV
• vasodilation to working muscles

Question 23

While we exercise, what muscular changes do we need to see happen so that we can get enough ATP? (3)

Answer 23

• increase Ca++ release/uptake by SR
• increased myoglobin shuttling
• increase in rate of Energy System pathway