Exam 1 Flashcards
Relationship between glycogen stores and fatigue
slow ATP production and increased cellular acidosis which promotes fatigue
What does beta-oxidation produce?
H+ for electron transport chain and acetyl-CoA for Kreb’s cycle
At rest, what is providing 50-90% of energy?
lipids
what is alanine important source of?
gluconeogenesis in the liver during long term endurance exercises
how is the rapid synthesis of ATP accomplished during the first 6-8 seconds of exercise?
hydrolysis of creatinine phosphate
How long should a glycolysis exercise test be?
longer than 6-10 seconds but shorter than 3 minutes
what does peak power output assume?
CP-ATPase capacity is tested
what does average power output assume?
glycolytic capacity is tested
what does the O2 deficit during the transitional stage represent?
the energy that was provided by anaerobic metabolism
during submaximal exercise, where is the majority of energy derived from?
aerobic processes
at a steady state in sub maximal exercise, what is there a balance between?
energy demand (energy expenditure in kcal) and oxygen uptake (L/min) which is why VO2 is a good index of energy expenditure
Health related components of physical fitness
cardiorespiratory endurance or fitness, body composition, muscular strength and endurance, flexibility
what is Vo2max?
the maximal capacity to transport and utilize oxygen (capacity for aerobic transfer)
Cardiorespiratory endurance/fitness
ability to perform large muscle, dynamic, moderate to high intensity exercise for prolonged periods
what is low level cardiorespiratory fitness associated with?
markedly increased risk of premature mortality from all causes, especially cardiovascular disease
what is increased cardiorespiratory fitness associated with?
a reduction in death from all causes
higher levels of habitual physical activity, which in turn is associated with health benefits
purposes of cardiorespiratory fitness testing
- obtain data needed for writing exercise prescriptions
- evaluation of progress in an exercise program
- motivation via provision of realistic exercise goals
- education on current fitness status
- health related risk stratification
What type of subjects are typically tested in health-related cardiorespiratory fitness testing?
asymptomatic adults
purposes of clinical exercise testing
- diagnostic testing
- testing for disease severity and prognosis
- clinical management
- pre and post discharge testing
- functional testing
Common ECG finding with myocardial ischemia
ST segment depression or elevation
purpose of ECG monitoring
- assess presence and severity of CAD
- predict likelihood of future cardiac events
- analysis of exercise induced arrhythmias
What is radionuclide exercise testing and why is it important?
radionuclides are rapidly taken up by cardiac muscle
the pattern and rate of uptake and clearance provides information on myocardial perfusion and ventricular function
what can assessing myocardial profusion detect?
coronary artery stenosis and muscle ischemia
what is radionuclide exercise testing clinically used for?
diagnosis of CAD in symptomatic individuals
prognosis of future event in patients with stable CAD
post MI assessment of myocardia ischemia, viability and ventricular function
What does stress echocardiography give information on?
- myocardial contractility
- cardiac volumes (ejection fraction)
- valvular function
what is the major use of stress echo and radionuclide imaging?
detect ischemic coronary artery disease
what is the gold standard for determining aerobic capacity?
directly measuring VO2 max
disadvantages of directly measuring VO2 max
- costly equipment
- specially-trained personnel
- time-consuming
- requires subjects to exercise to volitional fatigue
what is the second most accurate way of evaluating/determining aerobic capacity?
estimating VO2 max from maximal exercise testing (often used in clinical SLM-GXT)
how do you estimate VO2 max from a submaximal testing protocol?
- determine HR-VO2 relationship during progressive submax exercise or determine HR-exercise intensity relationship during submax exercise
- predict VO2max from the relationship determined using prediction equations
Primary criteria for reaching VO2 max
plateau in oxygen uptake with a further increase in workload
secondary criteria for reaching VO2max
- fatigue
- respiratory exchange ratio greater than or equal to 1.10
- HR during last stage that is within 10 beats per minute of age predicted max HR
- future of HR to increase with an increase in intensity
- RPE greater than 17 (on 6-20 scale) or greater than 9 (on 0-10 scale)
- post exercise venous lactate > 8 mM
what can influence RPE?
mood state, environmental conditions, exercise modes, and age
what factors can affect VO2 max?
- mode of exercise
- genetics
- gender
- body size and composition
- obesity
- aging
- activity level/training
what mode of exercise testing usually results in the greatest VO2 max value?
treadmill test
what factors contribute to the gender differences in VO2 max?
body composition, Hb concentration, variations in physical activity
what is VO2 max proportional to?
amount of contracting muscle
what do variations in body mass explain?
nearly 70% of the differences in VO2 max and accounts for most of the gender differences in VO2 max
how does age affect VO2 max?
VO2 max rises during childhood and peaks around age 20-25
decreases with age (about 1% per year after 25yo)
What is glucose converted to?
pyruvate then to either lactate or acetyl-CoA
What is EPOC?
difference between VO2 measured after exercise and the actual resting VO2 measured prior to exercise
Should be equal to the O2 deficit present before reaching steady state
Fast component of EPOC
- resynthesizes CP and ATP stores in muscle
- replaces oxygen stores in blood, body fluids, and myoglobin
slow component of EPOC
- lactate removal
- elevated core temp
- elevated hormones
- O2 demands of heart, respiratory muscles, etc during recovery