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final exam: training

Terms in this set (74)

how does endurance training improve vo2 max?
there is an increase in CO and a-vo2 difference
what factors influence CO?
an increase in SV which is increased by an increase in preload and decrease in afterload
what 3 factors influence SV?
1. preload
2. afterload
3. contractility
what 3 things influence preload?
1. increase in PV
2. increase filling time and venous return
3. increase in ventricular volume (size)
what factors influence a-vo2 difference?
increase in muscle blood flow and increase in capillaries mitochondria
what causes an increase in muscle blood flow and a decrease in afterload?
a decrease in SNS activity to working muscles (decrease in vasoconstriction and increase in vasodilation)
as training increases, SV
increases
what factors influence preload (influences SV)?
an increase in preload is influenced by:
- increase in PV
- increase in venous return
- increase in LV size
- decrease in HR
what factors influence contractility (influences SV)?
- LV size
- frank starling mechanism
the more blood in LV, more LV will stretch causing a stronger contraction of LV leading to greater SV
Frank-Starling Mechanism
what factors influence afterload (influences SV)?
- decrease in TPR due to decrease in vasoconstriction
- increase in maximal blood flow with no change in mean arterial pressure
as training increases, CO...
increases
what is the main reason/factor vo2 max increases with endurance training?
there is an increase in SV
what 2 main variables help increase a-vo2 difference with endurance training?
1. increase in muscle blood flow
2. increase in mitochondria
explain how an increase in muscle blood flow contributes to an increase in a-vo2 difference
- there is a decrease vasoconstriction of the smooth muscles surrounding the arteries meaning less blood flow to skin, GI tract
- increase in vasodilation allowing for o2 to enter muscles
- improved ability for muscle to obtain o2 from blood
explain how an increase in capillary density/mitochondria contributes to an increase in a-vo2 difference
- more capillaries=more o2 to muscles
- decreased diffusion distance to mit.
- increase in mitochondria increases muscle fibers ability to consume more oxygen
what is another important factor that contributes to an increase a-vo2 difference with endurance training?
an increase in blood volume caused by an increase in plasma volume
growth of new blood vessel/capillaries
angiogenesis
with endurance training, what 3 things happen to blood volume?
1. total blood volume increases (bigger increase)
2. hematocrit decreases
3. slight increase in RBC (less increase) (effects hematocrit)
less oxygen getting into the cells due to endurance training
sports anemia
how does endurance training influence our muscle fibers?
there is a shift from fast twitch to slow oxidative muscle fibers as we endurance train
how does endurance training influence our capillaries?
there is an increase in capillaries leading to enhanced diffusion of o2 and increased removal of wastes
how does endurance training influence our myoglobin?
there is an increase in myoglobin which supports oxidative capacity in muscle
how does endurance training influence our oxidative enzymes?
there is an increase in oxidate enzymes (SDH, citrate synthase) which help promote fat metabolism and spare glycogen
(promotes aerobic metabolism)
how does endurance training influence our o2 deficit?
when we are more aerobically trained, our o2 deficit is shorter because the supply for oxygen meets the demand quicker
why is there a decrease in o2 deficit to those who are endurance trained?
- increase in mitochondria/capillaries
- more blood flow to muscles
- more oxidative enzymes
what 2 things decrease when we have a faster rise in o2 uptake?
- less lactate formed
- less phosphocreatine depletion
as mitochondria increase, performance...
increases due to changes in muscle mtabolism
why does our performance increase as mitochondria increase?
- we have less reliance on glycolysis (rely more on aerobic)
- less lactate and H+ production
(delay in reaching lactate threshold and acidic environment meaning our performance can increase)
endurance athletes can be at an increased intensity before reaching what threshold?
lactate threshold
endurance training causes an increase in mitochondria. what 2 things does an increase in mitochondria have an effect on?
1. increase FFA oxidation and decreased PFK activity (more aerobic metabolism)
2. increased mitochondrial uptake of pyruvate and NADH (more aerobic metabolism)
how does an increase in FFA oxidation and decreased PFK activity due to increased mitochondria effect pyruvate?
there is a decrease in pyruvate formation meaning less lactate and H+ formation
how is pH effected when there is a decrease in lactate and H+?
pH is maintained
what helps with the sparing of plasma glucose and muscle glycogen in endurance training?
1. increase fat utilization/metabolism
2. transport of FFA into muscle
3. increase in mitochondrial oxidation of FFA
how does the body increase the transport of FFA into the muscle?
- increase capillary density (more blood flow to muscle=more FFA into muscle)
- increase fatty acid binding protein and fatty acid translocase (CD36) (helps transport FFA into muscle quicker)
how does an increase in mitochondrial oxidation of FFA help spare plasma glucose and muscle glycogen?
there is an increase in enzymes of B oxidation (fat metabolism) which increases in acetyl CoA formation
what happens to respiratory exchange ratio during endurance training?
it will decrease because we are relying on fat metabolism (lower RER, more fat met.)
what effects does endurance training have on free radicals?
it causes an increase in free radicals which can impair the contraction process.
what is released during endurance training to help sequester free radicals?
endurance training enhances antioxidants that help sequester free radicals
what antioxidants are found in the mitochondria?
1. superoxide dismutase (SOD)
2. catalase (CAT)
what antioxidants are found in the cytosol?
1. superoxide dismutase (SOD)
2. catalase (CAT)
3. Vitamin c (Vit C)
after 2 weeks of detraining, what decreases the most?
SV (VO2 max and CO also decrease)
what takes the longest to decrease during detraining following endurance training?
a-vo2 max
with detraining after endurance training, what happens to mitochondria?
it drops quickly (if you stop training for a week, it drops by 50%)
how long does it take in retraining for mitochondrial to get back to its elevated levels?
about 5 weeks
what are the 2 main components that contribute to an increase in strength?
1. neural component
2. size and number of muscle fibers
what are the steps that lead to a muscular contraction?
1. the higher brain centers found within the central command center of the brain send neural messages to spinal cord
2. the spinal cord delivers signal through the alpha motor neuron that innervates skeletal muscle fibers at the NMJ. NMJ tells muscles to contract
what are the 5 neural adaptations that occur due to resistance training?
1. increased ability to recruit motor units
2. increased firing rate of motor units
3. enhanced motor unit synchronization (motor units fire quickly and together)
4. removal of neural inhibition (with strength training, you can turn off GTO inhibition. to accomplish this you must perform overload to increase strength)
5. improved neural transmission across NMJ
what is "cross education"?
when one limb experienced education benefits of the nervous system
what are the physiological effects of resistance training on the nervous system?
1. increase in force production of type 1 muscle fibers
2. hyperplasia
3. hypertrophy
how is there an increase in force production of type 1 muscle fibers with strength training?
there is increased calcium sensitivity resulting in a greater number of cross-bridges bound to actin
- this means it takes less calcium in muscle contraction cycle
what is hyperplasia?
increase in number of muscle fibers/sarcomeres
what is hypertrophy and why does this occur with strength training?
- an increase in muscle size due to more contractile proteins present (happens after neural adaptations)
- increase in actin and myosin (muscle proteins) due to more sarcomeres
look at the bottom three of this chart**
resistance training increases:
1. muscle antioxidant capacity (12 weeks of training increase antioxidant enzyme)
2. tendon and ligament strength (harmonized increase in tendon/ligament strength to match increase in muscle strength)
3. bone mineral content (stronger bones)
are strength gains or endurance gains lost faster?
endurance gains
are strength gains or endurance gains recovered faster following detraining?
strength gains
what muscle fiber type is there a significant drop following detraining, however they recover significantly after retraining?
type 2x
the balance of protein synthesis and degredation
muscle protein balance
the longer we are inactive, what can occur?
inactivity induced muscle atrophy
what happens to protein synthesis/degradation as we become inactive?
synthesis decreases and degradation increases
what happens to protein synthesis/degradation as we become active?
synthesis increases and degradation decreases
enhances protein synthesis. the less we have, the more muscle atrophy will occurs
mTOR
how does endurance training before strength training inhibit strength gains?
when we endurance train, PGC1-alpha is released which promotes the production of mitochondria. PGC1-alpha inhibits mTOR which is critical for singling protein synthesis. therefore if we endurance train before we strength train, we are inhibiting our protein synthesis (mTOR) from occurring due to the release of PGC1-alpha
if the goal is to increase strength, should we do endurance or strength training first?
strength training first
Endurance training has been shown to reduce the oxygen deficit in subjects performing a submaximal exercise. This is due to
increases in the number of mitochondria and capillaries.
Which of the following factors does NOT contribute to the endurance exercise training-induced improvement in stroke volume during exercise? (Increased end-diastolic volume, Decreased in total peripheral resistance, Increased cardiac contractility)
Increased peripheral resistance
Ventilatory Threshold is ___________ in endurance-trained individuals.
higher
How does increased mitochondria improve endurance performance?
Less lactate production
Which is a mechanism for increased muscle strength
Increased myofibrillar proteins
Endurance training increases antioxidant production. How can that increase performance?
Decrease risk of muscle damage
Which variable decreases very quickly during detraining?
stroke volume
Which is a neural adaptation to resistance training?
Increase in the firing rate of motor units
What happens to muscle fiber type following resistance training?
Shift from fast to slow fibers
How does endurance training inhibit strength gains?
Endurance training inhibits mTOR
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