34 Physiological adjustments to exercise Flashcards
what is VO2 max?
the maximum about of O2 that a person can consume during physical work, and is a measure of maximum cardiovascular function.
T/F Ventilation is often the limiting factor for VO2?
False, this is almost never the case. The exception would be with someone with lung disease.
what happens to cardiac output during exercise?
It will increase 5 fold!
However, if you are a trained athlete like me, it can increase up to 8 fold and put out 40L/min.
What is the VO2 max equation?
VO2 max= CO(max) x (a-v)O2 difference (max)
what is aerobic power?
aerobic power is a measure of the maximal amount of external physical work a person can perform over a given period.
(its VO2 represented in liters/min)
what happens to blood lactate as you reach and exceed your VO2 max?
lactate levels shoot up dramatically because the body has to do more anaerobic respiration to keep up with the demands.
If you have an athlete and a non-athlete who become injured and are bedridden for 4 weeks, which of the two will have a lower VO2 max?
Well, the person who started with the lower VO2 max which would be the non- athlete. However, the athlete would have a greater (percentage) reduction in VO2 max over the time period. Basically, the more you have, the more you loose in the same time frame.
T/F The lower the initial level of max VO2, the greater the increase with training?
True
what causes the increases in VO2 max in a child? an adult?
child (due to increases in SV and a-vO2 difference.
adult (only due to SV increases)
What is the trend for VO2 max in life? at what age are you at your peak?
initially it increases until puberty, then falls. It once again increased during the late teens up to the age of 20. From 20 its all down hill.
why do women generally have lower VO2 max values?
Because of lower hemoglobin.
T/F Men and women have about the same VO2 max values before puberty?
True.
what does the ATP-phosphocreatine system do?
It allows for quick energy by adding a phosphate to ADP. The enzyme is called creatine kinase (CK)
ADP + phosphocreatine—->creatine + ATP
If I get up from my resting position, which energy method am I primarily using?
primarily the ATP-phosphocreatine system (<60 seconds)
T/F PCr energy can be used directly for cellular work?
False, PCr has to first be added to ADP so that work can be done.
How long does it take for PCr to become regenerated during rest?
about 3 minutes
when breaking down glycogen and using it in glycolysis, how much energy do I get? How much energy from glucose?
Glycogen= 3 net ATP Glucose= 2 net ATP
How long can the glycogen pathway sustain my energy demands during exercise?
up to 2 minutes (other source notes say 1-5 min)
what are some CONS about using glycolysis?
1) inefficient
2) buildup of lactic acid
3) lactic acid can impair further glycolysis and muscle contraction.
what are some PROS about using glycolysis?
1) fast
2) anaerobic
3) allows for short term high energy exercise
how much ATP will be generated using glucose through the oxidative system? Glycogen?
glucose=32 ATP
glycogen=33 ATP
How many ATP are produced through the breakdown of palmitic acid?
106 ATP
what is the major source of energy for oxidative phosphorylation?
triglycerides (one glycerol and 3 fatty acids)
How does the body use the triacylglycerides?
triacylglycerides–>lipase–>glycerol and fatty acid–>mitochondria beta oxidation–> acetyl Coa—>Krebs cycle–>ETC
What is the RER?
Respiratory Exchange Rate. It is a measure of gas exchange at the lung.
RER=volume of CO2 produced / volume 02 uptake
what does a RER of 1.0 mean? what about 0.7?
RER of 1.0 means the body is burning all carbs
RER of .7 means the body is burning mostly fats
(anywhere in between would be a mixture of the 2)
above exercise intensities of 70% of maximum, what is the main source of energy?
Glucose
What is the idea behind glycogen sparing with physical training?
It states that the better shape that you are in, the more that you will use fats, and your glycogen stores will be higher than in a non trained individual.
which type of tissue in the body has the greatest capacity to increase its metabolic rate?
muscle tissue
what innervates type 1 slow twitch muscle fibers?
what about type 2?
small A(alpha)2 motor neurons larger A(alpha)1 motor neurons
Type I fibers are called what?
Type IIa fibers are called what?
Type IIx fibers are called what?
Slow oxidative fibers (SO)
Fast oxidative glycolytic fibers(FOG)
Fast glycolytic fibers (FG)
what percent of muscle fibers are SO? FOG? FG?
SO—50%
FOG—25%
FG—25%
(note that long distance runners would have more SO fibers while a body builder would have more FG fibers)
what determines what percentage of SO, FOG, and FG fibers you have?
mainly genetics, but some training.
What is the Henneman size principal?
It states that are you go to pick something up, you activate the type 1 fibers first, and if there isn’t enough strength, then type 2 motor neurons are activated to move the object.
Exception: high velocity activities
In general, Type IIa fibers are intermediate between type I and type IIx muscle fibers. The exceptions are?
Type IIa: So these are not considered intermediates and are like the type IIx muscle fibers
Speed PC stores glycogen stores mysosin ATPase activity glycolytic enzyme activity
How does muscle get bigger?
Through hypertrophy and not hyperplasia. Increase in sarcomeres predominantly in type II fibers.
what does strength training do to muscle fibers as far as size?
strength training causes hypertrophy in both types, and that is about it.
Note: lactate buffering capacity also increases with anaerobic exercise training.
In general what does endurance training do for ST fibers and FT fibers?
The effects are the same for both all types!
1) increased oxidative capacity
2) increased glycogen content
3) increased fat oxidation
4) increased capillary density
5) increased mitochondria
Strength gains in the initial six weeks of going to the gym are due to?
improved motor recruitment
suppression of self protective reflexes
T/F endurance exercise does not enhance strength gains from resistance exercise, but resistance exercise does improve endurance exercise performance?
True
