Exercise Flashcards
Why are the categories of physical activities we are engaged in?
everyday activity, especially manual jobs
active recreation
sports
What is VO2 max?
The maximal oxygen consumption measured during incremental exercise
What is VO2 max a good indicator of?
physical aerobic capacity
How much oxygen is dissipate with heat?
80%, only 20% goes into doing the exercise
Which major artery is the first to get constricted upon intense exercise
splanchnic artery
What are the vasodilators involved in heat dissipation
metabolic vasodilators from contracting muscles
NO from endothelium
ATP from unsaturated hemoglobin
Why is postural hypertension common post-exercise?
because the MAP is sharply decreased due to muscular vasodilation. BP cannot keep up
How do we avoid postural hypertension after exercise
raise the legs and hydrate
Why do athletes have a slower heart rate?
Because the stroke volume is higher
T/F the period of systole gets extended in an athlete
False, the diastole increases and slows down the HR
Why do athletes use EPO?
although exercise increases blood volume, it also dilutes RBC. EPO can increase RBC amount and increase O2 carrying capacity and CO
T/F Trained muscles have increased capillary recruitment
True, hence the total delivery of oxygen is enhanced
T/F Oxygen saturation is usually not as efficient at the lung when exercising
False, although pulmonary blood flow is faster, the max saturation can still be achieved in most people
T/F O2 plays a role in ventilation control
False
How does heat impair exercise capacity
dehydration
electrolyte imbalance due to excess sweat
blood diverted to skin rather than muscles
How is type I fibre different to type II fibre
type I - higher endurance, higher oxygen capacity
type II - higher force and power output, fatigue prone
T/F You can’t change the amount of type II fibres you have
False, it’s just extremely difficult, but it’s much easier the other way around
Why is the initial increase in muscle strength so quick with resistance exercise
You are increasing the amount of nerve innervation and motor unit recruitment
What are the mitochondrial adaptation with exercise?
increased mitochondrial density and oxidative enzymes
reduced CHO use and lactate production
increased fat oxidation
improved insulin action
Which glucose channel is upregulated on muscles with exercise?
GLUT4
What happens when athletes “hit the wall”
run out of carbohydrate and only rely on fat
Which fuel do we use during sprints
creatine
glycolysis
Which fuel do we use in endurance exercise?
aerobic metabolism of fat or carbohydrate
At what intensity is fat oxidation most efficient
~50% max intensity (VO2 Max)
Why do we use more carbohydrate when we grow older?
because the exercise we do is relatively higher in intensity
What is fatigue
inability to maintain the required or expected force or power output
When is fatigue pathological
when it manifests at rest
What are the feedback signals from the muscles to CNS
running out of ATP
build up of H+ and RoS
What do we look for on the ECG when putting a cardiac patient on the treadmill for exercise diagnosis
ST depression
What is the Bruce protocol (modified)?
incremental exercise diagnosis, gradually increasing the intensity to avoid premature fatigue
What is lactate a byproduct of?
glycolysis and also anaerobic metabolism
T/F LT is a better endurance predictor than VO2 max
True, because it reflects the mitochondrial capacity
How do we biochemically define a “fit” person
When a person can exercise at high intensity without producing a lot of lactate
What does lactate tolerance indicate
muscle oxidative capacity
What does the VO2 max indicate?
the max power output
T/F moderate level of exercise is maximally beneficial
False, low level of activity gives the sharpest gradient of benefit
T/F exercise improves glycaemic control
True
T/F Combined aerobic and resistance exercise is most beneficial
True
Why is resistance training beneficial?
it increases the amount of muscle, its protein/fat disposal rate and also the amount of GLUT4
T/F Genetics play a huge role in determining fitness and major illnesses
True, an active person with family history of diabetes has higher chance of getting diabetes than an inactive person with no family history
T/F Exercise prescription has a dose response relationship in general
True, but there are cases when it isn’t. Some individuals developed insulin resistance with exercise
What is the main influence on pharmacokinetics with exercise
blood redistribution - more to muscles, less to organs
T/F There is more plasma insulin with exercise
True, to increase glucose uptake from muscles
What are some mechanisms for exercise-induced hypoglycaemia?
accelerated insulin absorption
enhancement of insulin action
lack of decline in insulin secretion
How does exercise affect GTN uptake?
transdermal - with exercise and skin vasodilation, there is increased uptake
How does exercise affect salbutamol?
there is increased RR, so there is higher bioavailability. Drug effect comes on quickly, but also wears off quickly
How does exercise affect warfarin?
There is increased binding of warfarin to albumin and increased metabolism. There is decreased warfarin concentration, and less anti-coagulative effect
Why is there reduced digoxin effect with exercise?
Re-distribution to the muscles, hence diluting the amount of plasma digoxin
T/F Propranolol clearance is more dependent on the kidney
False, it’s more dependent on the liver. Atenolol is more dependent on the kidney
What are some side effects of exercise?
sudden cardiac death
bronchospasm
exertional rhabdomyolysis
increased accidental injury
Exercising 4 time a week doesn’t reduce the risk of nonsudden death much more than exercising 1 time a week. Why should we exercise 4 times a week then?
it reduces the risk of sudden death
