Physio 5

Question 1

arm vs leg exercise

Answer 1

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

Question 2

why does MAP increase more during arm work?

Answer 2

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.

Question 3

dynamic vs static contractions

Answer 3

static contractions cause the MAP to increase more than dynamic contractions. Static contractions of large muscle groups are the worst!

Question 4

blood pressure response to static exercise

Answer 4

blood pressure responds as a function of the % maximal voluntary contraction being performed

Question 5

how is energy for contraction supplied?

Answer 5

aerobically and anaerobically

Question 6

anaerobic ATP production

Answer 6

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

Question 7

aerobic ATP production

Answer 7

slower to turn on and less powerful than anaerobic mechanisms, but much greater in the capacity to sustain prolonged bouts of muscle contraction

Question 8

when is anaerobicly provided ATP important?

Answer 8

during transition period from one level of activity to a higher level of activity. whenever exercise demands exceed the aerobic threshold of the individual

Question 9

O2 deficit

Answer 9

created by anaerobic ATP mechanisms. paid back post exercise

Question 10

Respiratory exchange ratio (RER) during exercise depends on:

Answer 10

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)

Question 11

glucose uptake during exercise

Answer 11

increases during exercise despite decreased blood insulin levels. this is due to enhanced insulin sensitivity

Question 12

glycogen usage during exercise

Answer 12

glycogen utilization by skeletal muscle increases exponentially as VO2 increases

Question 13

when is glycogen depletion the main cause of fatigue?

Answer 13

when you are working at 75% of VO2 max. fatigue is likely due to other factors at different exercise intensities

Question 14

RER in trained vs untrained people

Answer 14

higher in untrained than that of a trained person at any given exercise intensity

Question 15

VO2 max changes due to rest and training

Answer 15

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

Question 16

Heart rate and stroke volume in trained vs. untrained

Answer 16

in trained person, lower heart rate and higher stroke volume. this is an important training effect

Question 17

rate-pressure product

Answer 17

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.

Question 18

amount of catecholamines during workout in trained vs untrained

Answer 18

less stress in a trained person, so less epi and norepi

Question 19

muscle adaptations to aerobic exercise

Answer 19

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

Question 20

blood pressure response to exercise

Answer 20

when work is performed, vasodilation occurs in a large active muscle group and vasoconstriction occurs in a relatively small inactive muscle group