Lesson 2 LO

Question 1

Discuss how different metabolic fuel sources are stored in the body

Answer 1

CARBS
muscle glycogen= about 79.5% of body’s carbs stored here and provides energy/fuel for muscle contraction

liver glycogen= about 20% of body’s carbs stored in the liver

plasma glucose= only about .5% of body’s carbs

FAT
adipose tissue, muscle, liver, plasma

PROTEIN
skeletal muscle, plasma membranes, globular proteins, free amino acids

Question 2

Explain factors contributing to resting metabolism

Answer 2

proporitonal to body size: surface area and FFM
decreases w age

RMR rate of energy expenditure that is required at complete rest for all cell function, maintenance of body systems, regulation of body temp

Question 3

Describe the metabolic effects of hormones and how their release changes with exercise

Answer 3

Increase FFA supply by stimulating lipolysis in adipose tissue: catecholamines, GH, cortisol, glucagon

Stimulate gluconeogenesis and glycogenolysis in liver: catecholamines, GH, cortisol, glucagon

Stimulate glycogenolysis in skeletal muscle: catecholamines

inhibit insulin release and stimulate glucagon release: catecholamines

attenuates glucose uptake in skeletal muscle : GH

indirectly promotes growh and repair of skeletal muscle : GH

aids in recovery and repair after strenuous exercise: cortisol

stimulates uptake of glucose by muscle/fat/liver, inhibits lipolysis in adipose, inhibits glucose release from liver: insulin

Question 4

Describe acute metabolism changes with increasing exercise duration and intensity

Answer 4

increased intensity= greater ATP from glycolysis
fast twitch fibers utilize more glycolysis
increased catecholamines

duration increases= more fat, less carb burned
more fuel from plasma sources and less from muscular sources bc muscular run out

Question 5

Describe how FFAs are mobilized from adipocytes during exercise

Answer 5

Fat oxidation is greatest during mod intensity (50-60 Vo2max) and BF to adipocytes is also greatest…BF decreases at higher intensities

lipolysis; hydrolysis of triglycerides into FFAs and facilitaed through HSL… stimulated by GH, cortisol, testosterone..inhibited by insulin

Question 6

Explain how glucose is mobilized and maintained during exercise

Answer 6

in skeletal muscle;

• facilitated by GLUT proteins
• GLUT4; activated by isnulin and muscular contraction

in plasma glucose;

• increase reliance on fatty acids
• attenuating glucose uptake into muscle
• obtaining glucose from liver

Question 7

Explain the principle of specificity

Answer 7

training should be relevant and specific to the sport that the person plays… metabolism; energy systems should also be specific to the sport that the person plays

Question 8

Explain the effects of endurance training on lactate production and clearance

Answer 8

• changes in blood lactate response to exercise reflect changes in glycolytic, citric acid cycle, ETC capacity
• endurance training increases the workload at which the lactate threshold and OBLA occur- less lactate produced at same workload

-factors influencing decreased blood lactate after endurance training:
less reliance on carb oxidation means less pyruvate being formed, increased mitochondria allow more pyruvate into citric acid cycle, greater removal of lactate to tissues such as liver

moderate intensity exercise facilitates lactate removal

Question 9

Explain the effects of endurance training on exercise economy

Answer 9

endurance training improves economy

physio factors; metabolic adaptations due to increased capacity to resynthesize ATP via oxidative phos= more mitochondria
fiber type; slow twitch fibers more economical

biomechanical factors; improved coordination of muscle recuirment and increaesd eleastic energy

a 5-10% decrease in economy may limit patien’ts ability to perform ADLs