ExPhys exam ch. 2+5

What are the three energy systems and how many ATP will each make

ATP-PC - .9

Glycolysis - 2-3

Oxidative - 36

What are the forms of CHO?

Glycogen and glucose

What is the determining factor of which energy systems are used at any point in time?

Intensity

How do the blood lactate levels compare for an individuals who is less aerobically fit with someone who is more fit?

Someone who is less aerobically fit will have more lactate in their blood due to their lower lactate threshold

Which energy systems are anaerobic?

ATP-PC and Glycolysis

What are the three buffering mechanisms for lactic acid accumulation?

Exhalation of CO2, CORI cycle, lactate shuttle

What happens to lactic acid during the CORI cycle?

It gets repurposed into glucose through gluconeogenesis

How does RMR and BMR compare?

Resting vs asleep and BMR is about 5-10% lower

How does RMR compare between men and women?

RMR higher in men due to more FFM (fat free mass - muscle and bone)

How does oxygen consumption levels relate to energy expenditure?

More O2 consumed the higher the energy expenditure

What is meant by the “point of determination with pyruvic acid?

Acetyl CoA or lactate acid

When does protein make its greatest contribution for energy?

When carbs are low or depleted

What is beta oxidation and how does it affect the use of the substrate fats for energy?

Beta oxidation is the process of breaking down fatty acids into Acetyl-CoA which enters the Krebs cycle to help produce ATP

The use of substrate fats for energy is a lot slower due to this step and requires more oxygen

What are key enzymes of the of each of the three energy systems?

ATP-PC: Creatine Kinase (CK)

Glycolysis: Phosphofructokinase (PFK) and Hexokinase (HK)

Oxidative: Citrate Synthase (CS) and Succinate Dehydrogenase (SDH)

How can enzymes of the three energy systems be increased?

Train that system

What is the function of the enzymes of the three energy systems?

Run systems more efficiently

What is RER?

Respiratory Exchange Ratio = VCO2 expired / VO2 consumed

What are typical RER values at rest and during mild, moderate, and intense exercise?

~0.76 at rest, ~0.8 during mild, ~0.9 during moderate, and 1.0 and higher during intense

What happens to RER as exercise intensity increases?

It increases with exercise intensity

What is EPOC used for?

Excess post-exercise oxygen consumption is used as an estimate of anaerobic system

How does EPOC relate to the oxygen deficit?

The oxygen deficit is when the O2 demand exceeds the supply at the start and EPOC is the excess oxygen used after exercise for recovery

How does fitness status and exercise intensity relate to EPOC?

With a better fitness level → higher point of lactate threshold → lower EPOC due to better recovery

Higher intensity produces larger EPOC due to higher O2 demand

How does lactate threshold relate to VO2 max of an individual?

What are parts of the aerobic system? (Krebs, NADH, FADH, etc)

Glucose → glycolysis → pyruvate → acetyle CoA → Krebs → NADH/FADH → electron transport chain → ATP

What is glycogen overshoot or supercompensation principle?

When depleting the glycogen stores via aerobic exercise followed by adequate CHO intake and rest

What is glycogen sparing and how to best achieve it?

Increase FFA utilization and allowing the body to save or spare glycogen use

How does cardiac output relate to VO2 max?

Higher VO2 max means higher cardiac output and the amount of blood circulated throughout the body in one minutes

Why is CHO the body’s preferred energy source?

it can be used in glycolysis and aerobic energy systems

6.3 ATP/O2 molecule

Fast

What factors contribute to the increase in VO2 max in response to aerobic training?

cardiac output and O2 enzymes

What changes occur in the muscle of in response to anaerobic training?

How does movement efficiency relate to the amount of oxygen consumed?

The ore efficient a movement is the less oxygen is needed to perform it

What are average and elite levels of VO2 (aerobic capacity)

Average: ~30-40 for men and ~25-35 for women

Elite: 70-85+ for men and 60-75+ for women

What is meant by oxidative capacity of a muscle?

its maximum ability to generate energy (ATP) using oxygen through aerobic metabolism

What factors explain the fatigue experienced by a distance runner in the end of a race?

glycogen depletion

accumulation of metabolic by products

failure of muscle contractile mechanism

Explain how lactate affects muscles and blood pH?

Increased lactate causes the associated increase in hydrogen which leads to the drop in pH

What factors influence RMR and BMR?

Body size, age, stress, hormones, temperature

What happens to lactate threshold as a result of aerobic training?

Increases

What is indirect calorimetry?

Measures oxygen consumption and CO2 production to estimate body’s energy expenditure

What is a metabolic analyzer used for?

tool used for indirect calorimetry that measures O2 and VCO2

What type of data does the use of a metabolic analyzer produce?

How does OBLA relate to LT?

OBLA occurs at a higher intensity than LT

What is “hitting the wall”?

Glycogen depletion and OBLA

How does Ventilatory Threshold relate to Anaerobic Threshold?

point when ventilation rate exceeds the rate of O2 consumption to get rid of CO2 and lactic acid.

Generally occur around the same time