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Exercise Physiology Exam 4

Terms in this set (84)

principles of training
overload, specificity and reversibility
overload principle
training effect occurs when a physiological system is exercised at a level beyonf which it is normally accustomed
specificity principle of training
training effect is specific to muscle fibers recruited during exercise, energy system involved (aerobic vs anaerobic), velocity of contraction and type of contraction
reversibility principle of training
gains are lost when training ceases
how to train to increase VO2 max
large muscle groups, dynamic activity, 20-60 min, 3 or more times a week and greater than 50% VO2 max
average VO2 max increase with endurance training
15-20%
individuals with high initial VO2 max experience _____________ _______-
smaller increases in VO2 max
individuals with high VO2 max may require ______ to obtain improvements
higher exercise training intensities (>70% VO2 max)
up to ___% increase in those with low initial VO2 max
50
heritability determines approximately __% of VO2 max in sedentary adults
50
large variations in training adaptations reveal that __________ of training adaptations is approx 47%
heritability
VO2 max is defined by the ____ equation
Fick
Fick equation
VO2 max = max cardiac output X a-vO2 difference
differences in VO2 max between individuals are primarily due to
differences in SV max
short duration training improvements in VO2 max
4 months, increase in stroke volume
long duration training improvements in VO2 max
28 months, both stroke volume and a-vO2 increase
training increases max stroke volume by
increasing preload (EDV) and decreasing afterload (total peripheral resistance) , hydration, increasing plasma volume, venous return, contractility and ventricular volume
decreasing afterload (total peripheral resistance) causes
decreased arterial constriction, increased maximal muscle blood flow with no change in mean arterial pressure
Numerical training induced changes to stroke volume
11% plasma volume, 7% VO2 max, and 10% stroke volume within the first 6 days of endurance training
training-induced increases in arteriovenous O2 difference
muscle blood flow (decreased SNS vasoconstriction), and improved ability of muscle fibers to extract and utilize O2 from the blood, increased capillary density and slower blood flow through muscle
__ months of training has shown adaptation in arteriovenous O2 difference
32
increase in mitochondrial _____ and _____ with increased aerobic exercise
number and size
mitochondrial biogenesis
2012/2013 first mention, 2016-2020 most work done, today still identifying cell signaling pathways
mitochondrial homeostasis is preserved by
the fine coordination between two opposing processes: generation of new mitochondria, by mitochondrial biogenesis, and the removal of damaged mitochondria by mitophagy
the ability to perform prolonged, submaximal exercise is dependent on the
ability to maintain homeostasis
adaptations to muscle fibers as a result of endurance training
shift in muscle fiber type (fast to slow) and increased number of capillaries, increased mitochondrial volume, training-induced changes in fuel utilization, increase antioxidant capacity, improved acid-base regulation
shift from fast myosin to slow myosin isoforms
lower myosin ATPase but utilize less ATP - more efficient
increased number of capillaries surrounding muscle fibers means
enhanced diffusion of oxygen and improved removal of wastes
fiber type shift is dependent on
intensity and duration of training sessions, and total years of training
type 1 fiber shift is ________ but there is a genetic end point
progressive
endurance training increases _____________/__________ of both subsarcolemmal and intermyofibrillar mitochondria in muscle fibers
volume/size
increased volume and size of subsarcolemmal and intermyofibrillar mitochondria in muscle fibers improves
oxidative capacity and ability to utilize fat as fuel and increases mitophagy
mitophagy
selective removal of damaged mitochondria via autophagy -(phagocytes)
2 types of mitochondria
20% immediately below sarcolemma, and 80% dispersed around contractile proteins
mitochondrial volume can increase as fast as
5 days
prolonged endurance training can increase mitochondrial volume
50-100% in the first 6 weeks
increased mitochondrial volume results in
greater capacity for oxidative phosphorylation
when is there less O2 deficit
at the beginning of exercise
faster rise in oxygen uptake leads to
less lactate formation and less PC depletion
increases in the number of ADP transporters in mitochondrial membrane =
faster ADP uptake into mitochondria and lower cystolic (ADP)
cystol ADP is important because
results in less phosphocreatine depletion, less stimulation of glycolysis and less production of lactate and H+
increased utilization of fat and sparing plasma glucose and muscle glycogen because
increased transport of FFA into the muscle across the sarcolemma, increased capillary density, and increased fatty acid binding protein and fatty acid translocase (FAT) a fatty acid transporter moving FFA from cytoplasm into mitochondria
intramuscular fat provides
50% of the lipids oxidized during exercise and blood plasma provides the other 50%
endurance training-induced changes in fuel utilization
higher levels of carnitine palmitoyl transferase and FAT
mitochondrial oxidation of FFA
increased enzymes of beta oxidation, increased rate of acetyl-CoA formation, high citrate levels inhibits PFK and glycolysis
contracting skeletal muscles produce
free radicals which can cause dinner
training increases __________ (within your body) ________
endogenous antioxidant enzymes
endogenous antioxidant enzymes improve
the fibers abiolity to remove radicals, protects against exercise-induced oxidative damage and muscle fatigue
exogenous provided by
diet
cellular buffers
proteins, bicarbonate, and phosphate groups
blood buffers
bicarbonate, hemoglobin, and proteins
second line
respiratory compensation
muscle buffering during HIIT
increases
muscle buffering ______ _____ ______ during submax
does not change
lactate is formed anytime there is an accumulation of
NADH, pyruvate (in the cytoplasm), lactate dehydrogenase is present
training adaptations increase
mitochondrial number, NADH shuttles, and change in LDH isoform
less carbohydrate utilization =
less pyruvate formed
less NADH available for
lactic acid formation
endurance exercise training ______ acid-base balance during exercise
improves
exercise _________ cell signaling pathways that turn on transcriptional activators
stimulates
adaptation at muscle fiber level is the result of
an increase in specific proteins
exercise stress activates
gene transcription
___________ and __________ exercise training promotes protein synthesis in fibers
endurance and resistance
gene activation results in
transcription of mRNA
mRNA is
specific proteins amino acid sequence
muscle contraction activates
primary and secondary messengers
training induced muscle adaptation results in
expression of genes and synthesis of new proteins, mRNA leves typically peak in 4-8 hours and back to baseline within 24 hours
how often do you need to exercise to have training-induced mRNA adaptations
daily
mRNA leaves the cell nucleus, moves to cytoplasm where proteins are made, ribosome reads its base sequence and uses the genetic code to
translate into a corresponding amino acid
how do primary and secondary signals lead to muscle adaptations?
increased protein synthesis
specific muscle adaptive responses depend on exercise stimulus
resistance vs endurance training and intensity and duration of training
primary signals responsible for exercise-induced adaptation
mechanical stretch (resistance training), calcium (endurance training), sarcoplasmic reticulum release, AMP/ATP and free radicals (endurance training)
AMP
component in the synthesis of RNA
calmodulin-dependent kinases
activated by increases in cytosolic calcium-promotes activation of PGC-1a (transcriptional activator and regulator of mitochondrial biogenesis)
calcineurin (phosphatase)
activates T cells of immune system, participates in numerous adaptive reponses of muscle including fiber regeneration and a fast-to-slow shift in fiber type
nuclear factor kappa B
controls transcription of DNA, activated by radicals-promotes synthesis of antioxidant enzymes
mTOR (mechanistic target of rapamycin)
protein kinase- major regulator of protein synthesis and muscle size
secondary messengers in skeletal muscle
calmodulin-dependent kinases (CaMK), calcineurin (phosphatase), nuclear factor kappa B (NFkB) and mTOR
molecular response to bout of endurance exercise in seconds
increase calcium, free radicals, AMP/ATP
molecular response to bout of endurance exercise in minutes
increase calcinurin, CaMK, AMPK, p38, NFkB
molecular response to bout of endurance exercise in hours
increase PGC-1a mitochondrial biogenesis
biochemical adaptations to training influence the
physiological response to exercise; decrease sympathetic, HR and ventilation
one-leg training studies illustrate that _________ signals from trained muscle are lower following training
afferent
training of one leg _________ _____ result in transder of training effects from one muscle to another
DOES NOT
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