Excercise phy exam 3

how does growth hormone help to maintain plasma glucose?

1. decrease of glucose uptake

2. increase lipolysis

3. increase gluconeogenesis

what are the 2 types of catecholemines?

epinephrine and norepinephrine

how do Epi and NE help to maintain plasma?

1. increase glycogenolysis

2. increase muscle glycogenolysis

3. increase lipolysis

4. insulin suppression

how does glucagon help to maintain plasma glucose?

1. increase liver glycogenolysis

2. increase gluconeogenesis

3. increase lipolysis

what four processes help to maintain plasma glucose?

1. increase glycogenolysis

2. increase lipolysis

3. increase gluconeogenesis

4. decrease tissue glucose uptake

what are the functions of insulin?

1. increase tissue glucose and AA uptake

2. increase glycogenesis

3. decrease gluconeogenesis

What is O2 deficit? 

The lag in O2 uptake at the onset of exercise before you reach steady-state (demand > delivery)

How does training affect the rate at which steady state is attained? 

Trained  (T) individuals will reach steady-state earlier than their untrained UT) counterpart

If T clients obtain steady state quicker, how does this affect O2 deficit?

Smaller O2 deficit

How can you minimize the O2 deficit prior to competition?

Warm up before, get BCS to start prior to competition 

After an exercise session, does your body instantaneously return to ‘resting’ state?

No

Mathmatically, RER is calculated as

VCO2 divided by VO2

What is excess post-exercise oxygen consumption (EPOC)

It is the excess O2 consumed immediately after exercise to recover and rerun to your resting state

Why does EPOC remain elevated after exercise?

the body requires extra energy and oxygen to restore internal balance and repair the physical stress caused by a workout

What is the lactate threshold (OBLA: onset of blood lactate accumulation)?

OBLA is the critical threshold at which lactate is produced and accumulated exponentially

At what relative exercise intensity does OBLA occur for trained individuals?

65-80% VO2 max

At what relative exercise intensity does OBLA occur for trained individuals?

50-60% VO2 max

At what relative exercise intensity does OBLA occur for untrained individuals?

50-60% Vo2 max

What is the respiratory exchange ratio (RER)?

Non-invasive method to estimate what type of fuel is being used for a particular activity

How is the RER calculated?

VCO2 (produced) divided by VO2 (continued)

Under what conditions must the RER be calculated?

During steady-state conditions

What is the fuel used when the RER is 0.70?

FAT is the predominant fuel source

What is the field used when the RER is 1.0?

CHO is the predominant fuel source

What is the fuel used when the RER is 0.85?

FAT and CHO are contributing equally

What are the 2 main energy sources used during exercise?

1. CHO

2. FAT

What 2 factors govern the selection of using either FAT or CHO as a fuel source?

1. Intensity 

2. Duration

At low intensity (long duration) what is the preferred fuel source?

Plasma FFA

At high intensity (short duration) what is the preferred fuel source?

Muscle glycogen

What is the crossover concept?

Gradual blending of fuel during exercise. Both CHO and FAT are always used, the magnitude of use however depends upon intensity and duration.

When do muscle and liver  glycogen stores begin to deplete?

60-90 minutes of moderate-to-vigorous continuous activities

What is the ramification of muscle and liver glycogen depletion?

Muscle fatigue, hypoglycemia  

Why is the total ATP production from FAT metabolism dependent upon CHO stores?

Malate and oxaloacetate

So, how does this (i.e., decreased CHO) affect the quantity of ATP derived from FAT metabolism? Decreased CHO will dramatically decrease the quantity of ATP derived from FAT metabolism. How and Why?

Krebs cycle is partially disabled, thus less efficient. Because Acetyl-CoA from B-oxidation cannot be fully oxidised via krebs cycle, ATP production is limited.

Can we use lactate as an energy source? How?

Yes! Cori cycle .

What are hormones?

Chemical substances secreted by endocrine glands and transported by blood to target tissues

What are the 2 major classes of hormones?

Steroid (lipid soluble) and non-steroid (non-lipid soluble)

What two intracellular mechanisms occur after the hormone binds to the receptor

1. Alteration of membrane transport 

2. G-protein activation

Generally, how do hormones influence membrane transportation

Hormone-receptor binding opens gates + Hormone-receptor binding activates carrier molecules

What is the function of the G proteins (cluster of proteins)

Serve as a communicative link between the hormone-receptor binding (on the surface) and the subsequent events that will occur inside the cell

Does O2 consumption increase instantaneously to steady state at the onset of exercise?

No

Why does the OBLA occur at a higher intensity in T vs UT individuals 

T individuals have less lactate accumulation compared to their UT counterpart at the same absolute intensities