Chapter 3: Bioenergetics of Exercise and Training

Question 1

OBJECTIVES:
Understand the terminology of bioenergetics and metabolism related to exercise and training.
* Discuss the central role of ATP in muscular activity.
* Explain the basic energy systems present in human skeletal muscle.
* Recognize the substrates used by each energy system.
* Discuss development of training programs that are based on bioenergetics/metabolism.

Question 2

Where is blood stored and what happens to it during exercise?

Answer 2

Blood is stored in the venous system and is shunted to the working muscles

Question 3

Arteries
Arterioles
Capillaries
Venules
Veins

Answer 3

Arteries—away from heart
Arterioles—Controls Blood Flow
Capillaries—Exchange O2, neutrients, hormones, etc.
Venules—Collect blood
Vein—Back to heart, low pressure

Question 4

Mjo

Major Functions of the Blood

Answer 4

Trasport O2
Acid-Base regulation

Question 5

Bioenergetics—

Answer 5

Flow of energy
Energy—The capacity to do work

Question 6

Catabolism

Answer 6

Breakdown of large molecules to release energy

(Exergonic—relase energy)

Question 7

Anabolism

Answer 7

The Synthesis of molecules using the energy from catabolism

(Endergonic—Takes energy)

Question 8

Metabolism is Catoblic or Anabolic?

Answer 8

Both Catabolic and Anabolic reactions

Very complex

Question 9

ATP
What does it stand for?
What is it made of?

Answer 9

Adenosine Triphosphate
——Transfer of energy from exergonic to endergonic reactions
——Body’s energy currency

Made of:
—Adenosine
—Triphosphate (3)

Question 10

Three basic energy systems exist in muscle fibers to replenish ATP:

Answer 10

——All systems are always active, making ATP——
It just depends on the intensity of the activity
1. The Phosphagen system
—Anaerobic
(ATP phase—Stored in muscle)

2. Glycolysis
   —Anaerobic (fast) ——End in lactate 120 secs
   —Aerobic (slow)
   Using Carbohydrates and calories for energy
3. The Oxidative System
   —Aerobic

Question 11

The Phosphagen System (AKA— the ATP––CP)
What is it? When is it active?

Answer 11

Stored ATP— (6-10 secs)
* Short-term,
* high-intensity activity
* At the start of ALL exercises
* Replenished ATP Rapidly

Key Compenents
* Adenosine diphosphate (ADP)
* Creatine Phosphate (CP)
* Creatine Kinase (CK)

Question 12

Key Components of the Phosphagen System. What is the major purpose of the phosphagen system? (ADP, CP, CK)

Answer 12

Stored ATP
Adenosine di[hpspahte (ADP)
Creatine Phosphate (CP)
Creatine Kinases (CK)

The major purpose of the phosphagen system:
——replenish ATP rapidly for continued intense exercise (up to ~10 sec)
——Stops ATP from dropping dangerously low

Question 13

How is ATP Stored? How much?

Answer 13

Stored in muscles
It doesn’t store much for more than a few seconds (80–100g)

More creatine phosphate than ATP

Question 14

How is ATP replenished?

Answer 14

ADP + Creatine Phosphate —≥ Creatine kniase = ATP + Creatine

CK gives ADP it’s phosphate to make it ATP. (10 secs)

re-phosphorylated

Were acidity is coming from—make fatigue

Question 15

Law of Mass Action

Answer 15

Concentrations of reactants or products (or both) in solution will drive the direction of the reactions

Controls what extent the Phosphagen system

Question 16

Glycolysis

Answer 16

The breakdown of Carbohydrate
Glycogen or Glucose stored in muscle is delivered in the blood to resynthesize ATP
Yeild 2 ATP

Question 17

Fast Glycolysis
Glucose + 2P + 2ADP ––> Lactate + 2ATP + H2O

Answer 17

Converts Pyruvate to Lactate
High inntenisty–120 sec

Catalyed

Question 18

Slow Glycolysis

Answer 18

Pyruvate shuttled to the mitochondria

Question 19

What is the Cori Cycle? How does it relate to Lactate?

Answer 19

End result is not lactic acid
Lactate can be transported in the blood to the liver, where it is converted to glucose.
(in Liver) Result of fast Lactate

Question 20

Krebs Cycle (“Slow”)
Glucose + 2P + 2ADP + 2NAD ––> 2Pyruvate + 2ATP + 2NADH + 2H2O

Answer 20

Pyruvate that enters the mitochondria is converted to acetyl-CoA.

• Acetyl-CoA can then enter the Krebs cycle.
  – the NADH molecules (from glycolysis) enter the electron transport system, where they
  can also be used to resynthesize ATP.

Question 21

What is LT and OBLA

Answer 21

• LT – the exercise intensity at which blood lactate begins an abrupt increase above the baseline concentration

Lactate Threshold
50%–60% in untrained people
70%-80% in trained Athletes *

*Onset of Blood Lactate Accumulation *
* OBLA is a second increase in the rate of lactate accumulation
* High intensities of exercise

Question 22

How much time does the systems take?
Phospagen
Fast Glycolotic
Aerobic Respiration

Answer 22

Phospagen — 8-10 sec
Fast Glycolotic—1-2 Mins
Aerobic Respiration—Unlimited

Question 23

Fat Oxidation ——The oxidative (Aerobic) System

What does is store?
What breaks it down?
Where does it go?
Where are free fatty acids?
How are fatty acids broken down?
What does it break down into?
How many molecules do you get from 1 glycerol? Total Fat?

Answer 23

Triglycerides stored in fat (Broken down by lipase)
Release fatty acids into the blood
Fat is inside muscles, too (Intramuscular)
–––fat is fuel–––

Free Fatty acids enter the mitochondria and are broken down by beta-oxidation

Breaks into acetyl–CoA, which enters the Kreb Cycle

1 molecule of glycerol=22 ATP
Total—Over 400

Question 24

Total Energy Yield From the Oxidation of ONE (18 carbon) TRIGLYCERIDE MOLECULE

How many totals?

Glycerol
18 carbon fatty acid

Answer 24

Total: OVER 400 ATP

Glycerol—22
Fatty Acid—441

Question 25

Protein Oxidation—The Oxidative (Aerobic) System

Answer 25

Protien is not a significant scource of energy
We don’t want to loose it
Breaks down into the Krebs Cycle

Question 26

ENERGY PRODUCTION & CAPACITY
Phosphagen
Glycolytic
oxidative

Answer 26

ENERGY PRODUCTION & CAPACITY
Inverse relationship btw Max rate of ATP production and
total amount of ATP is capable of producing over a long
period of time

Phosphagen
— ATP at High intensity
— Short duration
— 8-10 sec
— ATP Rate: Fast
—Amount of ATP: Low

Glycolytic
—Moderate/ High Intensity
—Short/medium duration
— 1-2 mins

Oxidative
—Low intensity
—Lonh duration
—unlimited time

Question 27

TABLE on p. 30

Question 28

SUBSTRATE DEPLETION & REPLETION
1. Phosphagen
2. Glycolytic

Answer 28

Phosphagen
–– Creatine Phosphate can be almost entirely depleted from high
exercise
— During a short recovery, replenish ATP
— (3-5 Mins) COMPLETE (8 mins)
—stick a creatine on a phosphate

Glycolytic
—DEPLENISH: Based on intensity
— Possible to use up all of them
—(primary for fast glycolysis)
— REPLENISH: Post-exercise carbohydrate ingestion (eat sugar and carbs)
—around (0.7—3.0g of carbohydrates ——2 hours)

Question 29

Bioenergetic Limiting Factors in Exercise Performance

Oxygen Uptake and the Aerobic and Anaerobic contribute to exercise

Answer 29

The Oxidative (Aerobic) System
needs Oxyg.

Question 30

OXYGEN UPTAKE
O2 Uptake (VO2)
O2 deficit

Question 31

Primary source of ATP at rest and during low- intensity activities
Uses primarily carbohydrates and fats as substrates

Answer 31

The Oxidative (Aerobic) System