Lecture 3 - Overview of exercise metabolism

Question 1

What are the ATP dependent processses in skeletal muscle

Answer 1

Cross-bridge cycling (myosin ATPase) - takes up the most energy

Sarcolemmal excitablity (Na+ / K+ ATPase) - depolarising and re-polarising

Calcium pumping into SR (SERCA - Ca2+ ATPase)

Question 2

Fatigue is often related to disturbances of the..

Answer 2

Na+ K+ balance

Question 3

because muscle is about 70% water there’s about a 4-fold increase in concentration when it’s reported as

Answer 3

wet , as opposed to dry

Question 4

many of the metablic pathways are sensitive to…

Answer 4

the level of ATP

Question 5

If you inject ATP into muscle what happens?

Answer 5

the metabolic pathways are deactivated

ATP levels are the regulating variable - if depleted, you turn on the metabolic pathways

Question 6

Fats can only be…

Answer 6

oxidised

Question 7

Protein is only used in the oxidative metabolism when the subject is

Answer 7

Exercising ALOT or starving

Question 8

PCr + ADP + H+ –>

Answer 8

ATP + creatine

Question 9

2ADP —>

Answer 9

ATP + AMP

Question 10

Glycogen + 3ADP + 3P(i) —>

Answer 10

2 Lactic acid + H+ + 3ATP

Question 11

What is the power of the energy systems?

Answer 11

The rate of generating ATP

Question 12

The power of the system is inversely related to the ..

Answer 12

capacity of the system - how long it can sustain ATP production

Question 13

The energy systems used at onset of exercise are

Answer 13

PCr and Glycolysis

Question 14

The heavier the weight lifted in resistance training, the more likely you will

Answer 14

occlude the oxygen supply by compresssing the capillaries

will start to rely of Creatine phosphate and other anaerobic substrates

Question 15

In aerobic exercise the oxygen uptake is linearly related to the …

Answer 15

power output / exercise intensity

once gone above the maximum, need to start using anaerobic systems

Question 16

true or false

Fat sources for energy expendture are at the highest proportion of fuels used during maximum exercise intensity?

Answer 16

False

make up a higher proportion of energy expendature in medium intensity exercise

Question 17

over time, muscle glycogen ____ as an energy source

Answer 17

decreases as an energy source, fat oxidation and glucose usage go up

Question 18

What are the main factors influencing exercise metabolism?

Answer 18

intensity and duration

diet - high carb high = more carb consumption

training

Environmental temperature - hot conditions tend to burn more carbs

Age and gender - older you get the more you burn fat (exercise intensity is increase)
Women tend to oxidise more fat than men, thought to be due to oestrogen