physiology of training Flashcards
why does exercise challenge homeostasis?
has to regulate temp, maintain PCO2 and PO2 levels, maintain MAP via vasodilation of muscle
- glucose uptake increases
- pH decrease
what are the three principles of training and examples for each?
overload: system is exercised at a level beyond which it is accustomed (ex: sprinter runs marathon)
specificity: training is specific to muscles involved, fiber type, energy system, velocity of contraction and type of contraction (ex: jumps to increase height)
reversibility: gains are quickly lost when overload is removed (ex: if you don’t exercise you lose what you gain)
to improve one’s vo2 max roughly what durations and intensities are required? is the latter different if you are sedentary or exercise trained?
training increases VO2 max: 20-60 minutes 3-5 x a week at 50-80% VO2 max
yes they are different, a trained individual needs >70% VO2 max while a sedentary individual needs 40-50% VO2 max
what are the range of VO2 max values measured in athletes, healthy individuals, and those with cardiovascular or pulmonary diseases?
athletes: 84 L/min
healthy individual 45L/min
cardiovascular or pulmonary disease : 13-22%
-a trained individual can only increase VO2 by 2-3 %
-sedentary can increase as high as 50% although genetics mainly determine VO2
what is the main variable from the fick equation that is responsible for large differences in VO2 max in diff populations ( from cross-sectional studies)
VO2= Q (avo2)
- avo2 shows a significant increase in VO2 max across different populations
- however largest differences are due to stroke volume
how does exercise training affect cardiac output and what are the underlying mechanisms.
- Q increases
- HR decreases
- SV increases
how can the aVO2 difference change with long term aerobic exercise training?
aVO2 difference is due to increased O2 extraction from the blood, but is NOT due to an increase in arterial PO2 content with training
can endurance training shift muscle fiber type
yes it can
how does endurance training affect mitochondrial content in the muscle?
endurance training increased mitochondrial content
- will increase 50-100% within the first 6 weeks of training
how does endurance training affect the O2 deficit
reduces the O2 deficit
- less lactate and H+ formation
- less PCR depletion
- less disruption of homeostasis
how does endurance training enhance FFA transport into the muscle from the plasma? what about from the cytosol into the mitochondria?
- muscle to plasma: increased capillary density, increase FFA binding protein, FFA translocase
- cytosol to mitochondria: increased mitochondria and increase FFA transporting enzymes
how does endurance training improve acid base balance during exercise? Is there an increased or decreased pyruvate formation?
- initial metabolic adaptation to endurance training are likely neural or neural humoral receptive changes
- there is a decreased pyruvate formation
- increased mitochondrial uptake of pyruvate and NADH so it evens out
Why is PFK activity reduced after exercise training? how would this affect lactate formation?
PFK is reduced after exercise training because mitochondria increases which decreases lactate and H+ ion formation
is there a link between muscle and systemic responses ( that is changes in epinephrine and norepinephrine concentrations) after endurance training?
-the sympathetic nervous system had been activated so decrease in epi and norepi after endurance training because need less stimulation after training
What is the difference between muscle strength and endurance?
muscle strength: increases contractile proteins
endurance: increases mitochondrial proteins
with endurance training if you train one side, the other will not see progress
with resistance training: if you train one side the other side will see neural adaptations
