Exercise physiology Flashcards
What are the two states of efficient energy generation and what is inefficient?
Efficient= rest and aerobic exercise
Inefficient= anaerobic exercise
What substrates do you burn during rest, aerobic exercise and anaerobic exercise?
Rest= fatty acids
Aerobic= glucose
Anaerobic= glucose
What O2 is used, ATP generated and CO2 produced during rest?
ATP= 44 ATP from 1 molecule fatty acid
23 O2
16 CO2
What O2 is used, ATP generated and CO2 produced during aerobic exercise?
1 molecule glucose- 38 ATP
6 O2
6 CO2
What O2 is used, ATP generated and CO2 produced during anaerobic exercise?
1 molecule glucose= 2 ATP
2 CO2
no oxygen
What is VO2?
Oxygen uptake
What is VO2 determined by?
- Ventilatory capacity to provide oxygen
- Circulation to deliver O2
- Muscle ability to utilise O2
What is respiratory quotient?
Also known as respiratory exchange ratio
CO2 produced / O2 consumed
It increases during exercise
How can maximal exercise ventilation be calculated?
Estimated as maximal volunatry ventilation
= FEV1 x 40
What is usually the rate limiting factor to maximise exercise in health?
Cardiac physiology- heart rate
What definies our level of physical conditioning?
The efficiency of mechanisms in muscle that convert O2 to ATP such as:
- muscular capillaries
- mitochondria
- oxidative enzymes
What is the ‘anaerobic threshold’?
The point at which oxygen demand is higher than oxygen delivery and energy must be generated by non-oxidative metabolism
What are the effects of deconditioning?
- Reduced muscular capillary numbers
- Reduced mitochondrial density
- Reduced oxidative enzyme concentrations
- Lower anaerobic threshold
What are different examples of exercise testing?
- cardiac stress testing
- exercise-induced bronchoconstriction
- walking or step tests
- cardiopulmonary exercise testing
What are the outcome measures of cardiopulmonary exercise testing?
-
What happens if the aerobic threshold occurs earlier than predicted?
The patient is deconditioned
What is there if the patient has significant ventilation reserve at the end of their cardiopulmonary test?
There is no ventilatory limitation
Why are cardiopulmonary exercise tests used?
- allows functional understanding of exercise limitation
- facilitates exercise counselling
- may diagnose exercise induced asthma or arrhythmias
- may help with warning signs of disease severity e.g. in CF
What are the benefits of exercise?
- Reduced all-cause mortality
- Cardiometabolic benefit
- Reduction in some cancers
- Improvements in mental health
What are the exercise recommendations in the general population?
150-300 minutes a week of moderate (brisk walking)
75-100 of vigerous
Include cardio and strength that involves all main muscle groups
What is exercised induced asthma?
It is acute and reversible
Symptoms appear during or after strenous exercise
Especially if breathing dry and cold air
How is exercised induced asthma diagnosed?
Bike or treadmill, 6-8 min test
Then measure spirometry pre and post (at 5,10,15,20 mins of exercise)
Also check after exercise with a bronchodilator
What is MVV?
Maximal voluntary ventilation
What might a patient have with a high MVV, predicted HR and VO2 and are well conditoned?
High MVV= no ventilatory reserve
May have cystic fibrosis
What is the difference in patients cardiopulmonary tests with and without CF?
A healthy patient will reach max exercise with ventilatory reserve, a patient with CF will achieve same maximal capacity but with no ventilatory reserve.
What is prehabilitation?
An intensive training programme to improve condition pre-operatively.
Why are CPETs performed pre-operatively?
To ensure patients can handle the stress of surgery
What is the oxygen pulse?
VO2/HR
O2 pulse reduced when stroke volume is limited
Stroke volume may be limited due to cardiac or coronary heart disease
What does having a reduced stroke volume mean for exercise?
There is reduced cardiac output and less ability to deliver O2.
Reduces aerobic capaity and limits exercise
