Energy systems Flashcards
(25 cards)
What is the first law of thermodynamics?
The body does not produce, consume, or use up energy, rather it transforms it from one form into another as physiological systems undergo continual change
What are the three energy systems, and what do they produce?
ATP-PCr system, glycolytic system, and oxidative system work together to produce ATP
What intensity does the ATP-PCr system primarily operate at?
Short, high-intensity efforts (e.g., sprinting, lifting) (Anaerobic)
What intensity does the Glycolytic system primarily operate at?
Dominates during moderate to high-intensity efforts lasting 10 seconds to ~2 minutes (Anaerobic)
What intensity does the Oxidative system primarily operate at?
Dominates during long-duration, low to moderate-intensity activity (e.g., endurance running)
How does the ATP-PCr system produce ATP?
Uses phosphocreatine (PCr) to quickly regenerate ATP
How does the Glycolytic system produce ATP?
Breaks down glucose/glycogen into pyruvate to make ATP
How does the Oxidative system produce ATP?
Uses oxygen to break down primarily carbohydrates and fats to make ATP
Explain how are the three energy systems interconnected?
The systems are interconnected working in a coordinated, overlapping manner during exercise.
ATP-PCr is used first, then glycolysis kicks in, followed by oxidative metabolism as duration increases.
The dominant system depends on the intensity and duration of activity.
What are the two key components of the oxidative system enabling aerobic metabolism?
The Krebs cycle(Citric acid cycle) and electron transport chain
Contribution of energy systems to ATP production depends on:
Intensity of muscular activity.
Duration of activity.
Define homeostasis
body’s ability to maintain a stable internal environment
What test and sample is used to establish the lactate threshold (LT1) and lactate turn point (LTP/LT2) ?
Graded exercise test (GXT) combined with blood lactate sampling
when is ATP used
at muscular cross bridges between actin and myosin during musclular contraction
What is the term alactic?
Without the production of lactate
What two stores does ATP come from at the start of exercise
Intramuscular stores
ATP-PCr stores
Why is IMTG important
Accessible energy during exercise
How many ATP are used for exercise?
2 are used, the other two are recycled into gycolisis
What is the enzyme converting pyruvate to lactate?
LDH
Why are internal acidic environments in the body negative to performance
Denatures enzymes
What is the benefit of lactate production
Delays fatigue
What is the exercise threshold where exercise becomes unsustainable ?
Heavy to severe
What are the ways the body controls acidity levels through homeostasis?
- bicarbonate buffer
- lactate production
What thresholds does the lactate test measure?
1st and second thresholds
