Flashcards in Chapter 34: energetics and physiology of Exercise Deck (18):
What is the effect of acute exercise on heart rate, stroke volume, cardiac output and muscle blood flow?
SV(volume of blood transported during ventricular systole) increases
CO=HR*SV= volume of blood pumped thru ventricles with each heart beat= about 5L/min at rest. also increases
What muscle regulate muscle blood flow
precapillary sphincter-band of smooth muscle that adjusts blood flow into capillaries mainly in the mesenteric microcirculation
Why does HR increase with acute exercise?
sensory input from proprioreceptors and chemoreceptors
why does SV increase with acute exercise ?
increased venous return (starling mechanism)
Why does muscle blood flow increase with acute exercise?
local control of vasculature, CNS, and hormonal mechanism
decrease in total peripheral resistance
What effect does chronic aerobic exercise have on heart rate, stroke volume, cardiac output and muscle blood flow?
stronger ventricular contractions lead to increase stroke volume and decreased heart rate to maintain a certain CO.
increased perfusion in skeletal muscle and decrease in MAP(mean arterial pressure)= CO *Pr (total resistance which blood must be pumped)
What is the primary fuel used in low intensity exercise?
plasma fatty acids
What is the primary fuel used in moderate intensity exercise?
fatty acids mainly and some glycogen
What is the primary fuel used in high intensity exercise?
mainly glygen storages
What is a type I, slow-twitch skeletal muscle
highly oxidative (more mitochondria)
increased lipid stores
What is a type II, fast-twitch skeletal muscle
lower mitochondria and lipid than type 1
fatigue more easily
higher glycogen stores
What is a type 2x, slow-twitch glycolytic skeletal muscle
lowest mitochondria and lipid content of all skeletal muscles
higher glycogen storages
Effect of insulin on glucose metabolism
cause GLUT 4 to transport glucose to be stroed as glycogen and FAs are transported into myocytes and stored as TG
increase in ATP and creatine phophate
Effect of exercise on glucose metabolism
1. ATP/CP activiated and used quick
2. Anaerobic glycolysis
low ATP produce lactic acid
3. aerobic metabolism
high ATP yield
produce co2 and h2o
What is VO2 max
-maximum capacity to transport and utilize oxygen during maximal exercise aka aerobic capacity
-gold standard of physical fitness
-measured in lab with increasing exercise until O2 consumption plateaus.
-can be increased by 10%-20% with exercise training
What is lactate threshold? what
point where lactate production is more than clearance during increasing exercise intensity. lactic acid measured in the lab in the blood during increasing exercise intensity.
Effect of lactate threshold on physical fitness. How does chronic exercise training affect lactate threshold.
exercise increases the threshold by increase VO2 so more energy is derived from aerobic processes