Physio 5 Flashcards
arm vs leg exercise
BP response is higher in arm work than leg work. TPR increases more during arm exercise so the MAP is higher for the same VO2
why does MAP increase more during arm work?
leg exercise has vasodilation in large muscle groups and constriction in small inactive muscle groups, while for arms, it is vice versa. since the large muscle groups are being constricted in arm exercise, the MAP rises more.
dynamic vs static contractions
static contractions cause the MAP to increase more than dynamic contractions. Static contractions of large muscle groups are the worst!
blood pressure response to static exercise
blood pressure responds as a function of the % maximal voluntary contraction being performed
how is energy for contraction supplied?
aerobically and anaerobically
anaerobic ATP production
fast to turn on in response to need, powerful in terms of maximal rate of ATP turnover, but limited in the capacity to sustain repeated contractions. stored levels of ATP can only provide for 2-3 contractions. levels of CrP are 3-4 times greater than ATP. myokinase is important in maintaining the ATP/ADP ratio. glycolysis has the greatest capacity of anaerobic mechanisms
aerobic ATP production
slower to turn on and less powerful than anaerobic mechanisms, but much greater in the capacity to sustain prolonged bouts of muscle contraction
when is anaerobicly provided ATP important?
during transition period from one level of activity to a higher level of activity. whenever exercise demands exceed the aerobic threshold of the individual
O2 deficit
created by anaerobic ATP mechanisms. paid back post exercise
Respiratory exchange ratio (RER) during exercise depends on:
the RER during exercise depends on exercise intensity, prior dietary history, exercise duration, and fitness level. RER increases as VO2 increases. Under steady state conditions, this reflects CHO use (sugar use)
glucose uptake during exercise
increases during exercise despite decreased blood insulin levels. this is due to enhanced insulin sensitivity
glycogen usage during exercise
glycogen utilization by skeletal muscle increases exponentially as VO2 increases
when is glycogen depletion the main cause of fatigue?
when you are working at 75% of VO2 max. fatigue is likely due to other factors at different exercise intensities
RER in trained vs untrained people
higher in untrained than that of a trained person at any given exercise intensity
VO2 max changes due to rest and training
decreases with rest and increases with aerobic training. decline in VO2 due to bed rest is much more pronounced than with simple cessation of training or a decrease in a habitual activity level
Heart rate and stroke volume in trained vs. untrained
in trained person, lower heart rate and higher stroke volume. this is an important training effect
rate-pressure product
RPP = HR x SBP. rpp is lower at any given work rate in a fit person vs. an unfit person. consequences: heart requires less oxygen, heart requires less blood flow, and the heart operates more efficiently.
amount of catecholamines during workout in trained vs untrained
less stress in a trained person, so less epi and norepi
muscle adaptations to aerobic exercise
aerobically trained muscle displays an increased mitochondrial content, and an increased capacity to synthesize ATP from free fatty acids. all muscle fiber types can increase mitochon content if used and stresed appropriately. increase in mitochon = an increase in improvement in endurance capacity, and a greater reliance on fat as a metabolic fuel at any given work rate
blood pressure response to exercise
when work is performed, vasodilation occurs in a large active muscle group and vasoconstriction occurs in a relatively small inactive muscle group
