Lecture 16 - Energy Systems and Exercise I Flashcards
Describe lactate recovery in skeletal muscle, blood and liver
In skeletal muscle - lactate converted back to pyruvate and used aerobically (recycled via NADH+ and NAD via Lactate Dehydrogenase)
From blood – can be transported to cardiac muscle and kidney, converted to pyruvate and used aerobically
From blood - transported to liver and converted back to glucose via Cori cycle
Describe lactate removal and describe what is the best way to lower lactate levels
Conversion of lactate to pyruvate in muscle is greater if low intensity aerobic activity performed (cool-down)
Most effective way to lower lactate levels quickly
What is EPOC and what does it represent?
Excess Post-exercise Oxygen Consumption (EPOC),
Elevated Oxygen Consumption: After exercise, the body requires more oxygen than at rest to restore physiological functions.
Energy Expenditure: EPOC represents the additional calories burned during the recovery period due to increased oxygen consumption.
What are the physiological processes involved in EPOC and excess oxygen consumption post-exercise?
Resynthesis of ATP and PCr (phosphocreatine) stores
Restoration of muscle glycogen stores
Replenishment of oxygen stores
Removal of lactate and other metabolic byproducts
Cooling down of body temperature
What influences EPOC with regards to training. What will result in a greater EPOC?
Influenced by the intensity and duration of exercise. Higher intensity and longer duration exercises generally result in a greater EPOC.
What is oxygen debt?
A temporary oxygen shortage in the body tissues arising from exercise is called oxygen debt. In details, Oxygen debt is the oxygen required (after vigorous exercise, using up the oxygen faster than it can be breathed in) to oxidize lactic acid, created from anaerobic cellular respiration.
During EPOC, oxygen consumption tapers in a negative logarithmic fashion. What explains the sudden drop in O2 consumption (fast component) then the gradual decrease in O2 consumption (slow component)
Fast component
* Reflects requirements to replenish ATP-PC system
Slow component
* Reflects elevated body temperature and thermogenic hormone effects on metabolism, cardiovascular & respiratory systems
What are the relative rates of the synthesis of ATP according to each of the 4 substrates: PC, Lactate (Glycerol and Glucose), Aerobic (Glycerol and Glucose), Aerobic
PC - 100
Lactate - 55
Aerobic (G) - 23
Aerobic - 10
Where do each of the 3 systems occur in the cell: Anaerobic-Alactate, Anaerobic-Lactate, Aerobic
Alactate - Cytoplasm of muscle cells
Lactate - Cytoplasm of muscle cells
Aerobic - Mitochondria of cells
What are the types of exercise during which each of the 3 systems better produce energy: Anaerobic-Alactate, Anaerobic-Lactate, Aerobic
Alactate - During short bursts of very high-intensity activities, lasting around 10-15 seconds
Lactate - During high-intensity activities when oxygen demand exceeds supply
Aerobic - Dominant during rest and low to moderate intensity activities, providing energy for everyday tasks and endurance activities.
What are the products in each of the 3 systems: Anaerobic-Alactate, Anaerobic-Lactate, Aerobic
Alactate: Creatine
Lactate: Lactate
Aerobic: ATP, CO2, H2O
What are the substrates utilised in each of the 3 systems: Anaerobic-Alactate, Anaerobic-Lactate, Aerobic
Alactate: Creatine Phosphate
Lactate: Glucose or Glycogen
Aerobic: Glucose, Fatty Acids
Large EPOCs are associated with a) what types of exercise, and b) which type of people
Associated with high intensity and long duration exercise
More common in fit people/elite athletes
Why can’t overweight/deconditioned people achieve large EPOCs?
Many overweight/deconditioned people can’t perform this intensity of exercise for long enough
At the onset of exercise, why is there an O2 deficit?
At onset of exercise, aerobic system takes time to increase ATP production
Initially, ATP comes from ATP stores & PC system
A measure of the ATP not provided aerobically is ‘oxygen deficit’
