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Physiology II > Exercise Physiology > Flashcards

Flashcards in Exercise Physiology Deck (32):
1

Oxygen consumption

Resting level of oxygen consumption:
SV, HR and breathing rate is low at rest
0-5:
Oxygen deficit - started activity
More oxygen required by working muscles that can be supplied until HR and BP catch up with initial start of activity
Connections between aerobic and aneorobic exercise

2

Onset

02 consumption rises exponentially for the first few minutes
Fast component of exercise 02 consumption

3

Plateau

Attained at 3-4 minutes

4

Continued exercise: stable, steady state

Remain stable for duration of effort
Balance between energy required and ATP produced by a aerobic metabolism
No blood lactate accumulates

5

What is the consequence of continued exercise

Fluid loss
Electrolyte depletion
Glycogen store depletion

6

Elite athletes

High capacity of central circulation to deliver oxygen to active muscles
High capacity of active muscles to use o2

7

What does pericardium limit?

Maximal oxygen consumption by limiting stroke volume and cardiac output during maximal response

8

What is maximal oxygen consumption limited by?

Oxygen transport capacity of the cardiovascular system

9

Define oxygen deficit

Difference between oxygen consumption during exercise and total that would have been consumed had steady rate O2 consumption had been achieved from start

10

What is the immediate source of energy

Anaeorbic glycolysis
Hydrolysis of high-energy phosphate ATP and PcR

11

What is recovery

How long it takes to return to pre-exercise oxygen consumption
Higher intensity of exercise produce more anaerobic energy transfer
Higher blood lactate
Higher BT

12

Light exercise

Aerobic
Rapid attainment if steady rate oxygen consumption

13

Moderate-intense exercise

More anaerobic energy transfer
Longer time to achieve steady-rate oxygen consumption
Larger oxygen debt
Recovery takes longer

14

What is fatigue?

Depletion of all ATP
Myoglobin has lost all O2
Glucose and glycogen depleted
High accumulated levels of lactic acid

15

What is EPOC

Breathing fast and deep following exercise to increase the amount of oxygen in the body to return the body to its pre-exercise state

16

O2 deficit

How much of your effort was aneorbic

17

Steady-state oxygen consumption

volume of oxygen consumed whilst exercising/during the event

18

Fast component of EPOC

What happens after 2-3 minutes after event
Uses additional 1-4 litres of oxygen
Resynthesise all ATP and PC
Replenish all myoglobin with oxygen
Synthesise 50% of PC stores within first 30 seconds

19

Slow component of EPOC

Removal of lactic acid
Maintenance of ventilation, circulation and body temperature
Require 5-8L of oxygen

20

Why does temperature take time to recover post exercise?

Higher temperature - more chemical reaction
More oxygen consumed

21

What does recovery depend on?

Activity:
Type,
Duration of exercise

22

What is VO2 max?

Maximum volume of oxygen used/ utilised by the muscles per minute
Measured in: ml/min/kg

23

Factors affecting VO2max?

Cardiac hypertrophy - Increase stroke volume and cardiac output
Increased haemoglobin levels
Increased capillary density
High percentage of slow twitch muscle fibres

24

Factors affecting V02 max

Age - decline from 25 years (1% per year) - lost elasticity of heart - less diffusion of oxygen into lungs and muscles

Gender: males higher than females (higher body fat and smaller lung volume)

Fitness

Genetics

Node of exercise

25

Assessment of VO2 max

Activate body’s large muscle groups
Incremental exercise test
Workload increases until exhaustion
expired air samples collected in last min of exercise and analysed for oxygen and carbon dioxide


Limitation: motivation

26

What are the 3 systems that max oxygen consumption depend on?

Respiratory
Circulatory
Muscular

27

Lactate threshold

Intensity of exercise at which lactate begins to accumulate in the blood at a faster rate than it can be removed

28

What is the causes of BLA?

Low tissue oxygen
Low blood oxygen
Low blood flow to skeletal muscle
Decreased redox potential
Reliance on glycolysis
Activation of fast twitch muscle fibres (type IIb)
Reduced lactate removal
Imbalance between production and removal

29

What are the symptoms of acute motion sickness?

Fatigue
Nausea
Decreased appetite
Laboured breathing
Tachycardia
Nerve dysfunction

30

Acute motion sickness

Increase ventilator drive due to decreased O2 causes respiratory alkalosis

31

What is acclimitaztion?

Aim is to restore normal acid-base balance for adequate oxygenation

32

What are the components of acclimitaztion?

Kidneys: excrete base HCO3- and conserve acid
Increased capillaries in tissue: reduced distance for oxygen diffusion
More mitochondria and oxidative enzymes: use oxygen more efficiently
Increased red blood cell production
Increased 2,3-BPG synthesis - increase oxygen unloading at tissues
Increased lung volume