Energy systems.

1
Energy systems.
2
PHYSIOLOGICAL REQUIREMENTS OF PHYSICAL ACTIVITY
Foods Fuel and Energy Systems
3
Where does this energy come from?
A Roger Federer serve takes 1-2 seconds to
perform. Its fast explosive. He might do this
hundreds of time over a game. Plus he has to run
fwd, bkwd and sideways for 1-2 hours. His Muscles
requires ENERGY to do this.
4
Food Fuels our Body
1. CARBOHYDRATES (Glycogen)
2. PROTEIN
3. FATS
5
CARBOHYDRATES
Pastas
Cereals
Rice
Fruit/Veges
Breads
Sugar
Carbohydrates are stored as Glycogen in Muscle
Liver
CHO is the bodys preferred fuel during Exercise
breaks down easily, uses little oxygen
6
PROTEIN
Fish
Red Meat
Poultry
Eggs
Dairy products
GRAINS
Protein is stored as MUSCLE and AMINO ACIDS
around the body.
5-10 contribution to endurance events Mainly
used for growth/repair
7
FATS
Butter
Oils
Margarine
Nuts
Cheese
8
Food that we ingest is stored and burnt to fuel
our muscles
This food must be converted into a chemical
compound called ATP
Without ATP - Muscles cannot contract
9
A.T.P.

• Adenosine triphosphate.
• This is energy for muscle contraction.
• Energy for movement of muscle fibres is stored in
  the muscle as a molecule of ATP.

Adenosine
P
P
P
Adenosine triphosphate
10
To use the stored ATP

• To release the energy, ATP is broken down into
  ADP Pi (Adenosine diphosphate Phosphate
  molecule)
• The energy released allows for a muscle
  contraction.

P
P
Pi
Adenosine
Energy
11
Resynthesis of ATP

• There is only enough stored ATP for about 1-2
  contractions, so.we must resynthesise ADP back
  into ATP.
• Fuel and energy for this comes from CHO, Fats,
  Proteins and Creatine phosphate.
• These fuel sources resynthesise the free
  Phosphate molecule (Pi) back to the ADP to reform
  ATP.

12
CHO, Fats, Proteins, CP

P
P
Pi
Adenosine
Resynthesises the ADP back to ATP
P
P
Pi
Adenosine
13
ATP is used in all 3 energy systems.

• The type of energy system used and the interplay
  between them depends on the frequency, duration,
  intensity of the activity and fitness levels of
  the individual.

14
The 3 energy systems

• The ATP PC system
• The Lactic Acid Systems
• Aerobic System

15
For activity lasting
0-10 SEC
ATP-PC SYSTEM
10-30/40 SEC
Anaerobic Glycolytic SYSTEM
2MINS
AEROBIC SYSTEM
16
High Energy Phosphate System
17
ATP PC system cont..

• ATP breaks down to ADP Pi to release energy.
• The ADP Pi must be reformed to ATP for
  continued muscle function.
• PC provides the energy for the free Pi to be
  re-attached to the ADP molecule to form ATP.

18
ATP PC system cont..

• PC stored in the muscles breaks down
  anaerobically (without O2) to form Phosphate and
  Creatine. This releases energy for the
  resynthesis of ATP.
• It takes 2 PC molecules to resynthesise 1 ATP
  molecule (one PC 0.7 ATP).
• NOTE The resynthesis of PC (Phosphate Creatine
  PC) occurs in the recovery phase.

19
ATP-PC SYSTEM
CP instantly available, but runs out quickly
Uses stores of CP (Creatine Phosphate) to REMAKE
ATP
Used for high intensity Jumps, Throws, Sprints
Only have 10 seconds of CP in muscles
If activity lasts longer than 10 sec, ATP must be
REMADE by some other means..
20
Training the High Energy Phosphate System

• a) Interval training
• - 20 increase in CP (creatine phosphate)
  stores
• - no change in ATP stores
• - increase in ATPase function (ATP -gt ADPP)
• - increase in CPK (creatine phosphokinase)
  function (CPK breaks down CP molecule and allows
  ATP resynthesis)
• b) Sprint training
• - increase in CP stores up to 40
• - 100 increase in resting ATP stores
  

21
Summary

• Each ATP molecule is made up of an adenosine part
  and three phosphate groups.
• Besides ATP, there is still another high-energy
  compound called phosphocreatine (PC) inside the
  human muscle cells. When PC is broken down,
  energy is released for the resynthesis of ATP.

22
Summary Cont

• However, the total amount of PC stored in the
  human body is also extremely limited. The energy
  released from the breaking down of ATP is also
  required to resynthesize PC. Nevertheless, this
  process will be carried out when the human body
  is in the recovery stage.
• The complete ATP-PC system can only supply 5.7 to
  6.9 Kcal of energy, which can maintain about 10
  seconds of maximal efforts.

23
Summary cont

• The importance of the ATP-PC system is that it is
  the instant energy source in the human body.
• The ATP-PC system does not require oxygen in the
  muscles for proper functioning. Besides, the
  required fuels (ATP and PC) have already been
  stored in the muscle cells
• The chemical reactions involved when PC is broken
  down are fewer than the other two energy systems.
• The ATP-PC system is particularly important for
  high-intensity and high- speed activities that
  need to be completed in a few seconds (e.g.,
  starting, jumping, throwing, and weight lifting).
  

24
Anaerobic Glycolytic SYSTEM
Body uses stored fuel of GLYCOGEN to REMAKE ATP
Need Oxygen to do this properly
About 2-3 hours of glycogen stored in body.
Downside by-product called Lactate. Hydrogen
Ions also released which inhibit muscle
contraction
Happens because of lack of enough Oxygen to break
down Glycogen
400m run, 800m at high intensity
25
The Anaerobic Glycolytic System
26
Glycolysis

• A biochemical process that releases energy in the
  form of ATP from glycogen and glucose
• Anaerobic process (in the absence of oxygen)
• The products of glycolysis (per molecule of
  glycogen)
• - 2 molecules of ATP
• - 2 molecules of pyruvic acid
• The by-product of glycolysis (per molecule of
  glycogen)
• - 2 molecules of lactic acid

27
Anaerobic Threshold

• The exercise intensity at which lactic acid
  begins to accumulate within the blood
• The point during exercise where the person begins
  to feel discomfort and burning sensations in
  their muscles
• Lactic acid is used to store pyruvate and
  hydrogen ions until they can be processed by the
  aerobic system

28
The Anaerobic Glycolytic System cont.

• Starts when
• the reserves of high energy phosphate compounds
  fall to a low level
• the rate of glycolysis is high and there is a
  buildup of pyruvic acid

29
Substrates for the anaerobic energy system

• The primary source of substrates is carbohydrate
• Carbohydrates
• primary dietary source of glucose
• primary energy fuels for brain, muscles, heart,
  liver

30
Carbohydrate breakdown and storage
31
Effect of Training on the Anaerobic Glycolytic
System

• Rate of lactate accumulation is increased in the
  trained individual
• This rate can be decreased by
• a) reducing the rate of lactate production
• - increase in the effectiveness of the
  aerobic oxidative system
• b) increasing the rate of lactate
  elimination
• - increased rate of lactic acid
  diffusion from active muscles
• - increased muscle blood flow
• - increased ability to metabolize
  lactate in the heart, liver and in non-
  working muscle

32
Review of Anaerobic Systems

• Video Review

33
AEROBIC SYSTEM
Plenty of Oxygen available to remake ATP . So no
LA or H is accumulated
Used in longer, sub-max activities. Long run,
swim, cycle.
Like the LA system, the Aerobic uses Glycogen to
remake ATP.
Oxygen supply meets demand
We use this system at REST (Now!) except we
burn
Will keep suppling ATP for as long as Fitness
levels allow
FAT!!!!
34
Aerobic Oxidative System
35
The Aerobic Oxidative System

• The most important energy system in the human
  body
• Primary source of energy (70-95) for exercise
  lasting longer than 10 minutes provided that
• a) working muscles have sufficient
  mitochondria to meet energy requirements
• b) sufficient oxygen is supplied to the
  mitochondria
• c) enzymes or intermediate products do
  not limit the Krebs cycle
• Primary source of energy for the exercise that is
  performed at an intensity lower than that of the
  anaerobic oxidative system

36
The Oxidative Phosphorylation System

• Two Pathways Krebs Cycle Electron Transport
  Chain
• Biochemical process used to resynthesize ATP by
  combining ADP and P in the presence of oxygen
• Takes place in mitochondrion (contains enzymes,
  co-enzymes)
• Energy yield from 1 molecule of glucose is 36 ATP
  molecules
• Energy yield from 1 molecule of fat up to 169 ATP
  molecules
• By-products of this reaction carbon dioxide,
  water

37
Cori Cycle

• Lactic acid is taken to the liver to be
  metabolized back into pyruvic acid and then
  glucose

38
Aerobic Review

• Video Review

39
The Power Of The Aerobic System

• Evaluated by measuring the maximal volume of
  oxygen that can be consumed per kilogram of mass
  in a given amount of time
• This measure is called aerobic power or VO2 max
  (ml/min/kg)
• Factors that contribute to a high aerobic power
• a) arterial oxygen content (CaO2)
• - depends on adequate ventilation and the
  O2-carrying capacity of blood
• b) cardiac output (Q HR x stroke volume)
• - increased by elevation of the work of heart
  and increased peripheral blood flow
• c) tissue oxygen extraction (a-vO2 diff)
• - depends upon the rate of O2 diffusion from
  capillaries and the rate of O2 utilization

40
The Substrates for the Aerobic System

• Carbohydrates (glycogen and glucose) and fats
  (triglycerides and fatty acids)
• Fats
• found in dairy products, meats, table fats, nuts,
  and some vegetables
• bodys largest store of energy, cushion the vital
  organs, protect the body from cold, and serve to
  transport vitamins
• each gram of fat contains 9 calories of energy

41
Effect of Training on Aerobic Systems

• Endurance training is the most effective method
  (long duration several times per week)
• - increases vascularization within muscles
• - increases number and size of mitochondria
  within
• the muscle fibres
• - increases the activity of enzymes (Krebs
  cycle)
• - preferential use of fats over glycogen
  during exercise
• Endurance training increases the max aerobic
  power of a sedentary individual by 15-25
  regardless of age
• An older individual adapts more slowly

42
During REST
Any rest, short OR Long, CP is being replenished,
so we can sprint again. BUT, need 3 minutes
rest to get all CP back!
Any Lactate and Hydrogen Ions are removed from
muscles blood stream too.
43
Things to remember
All 3 turn on at once no matter what the
activity.
However, depending on intensity and duration of
the activity, ONE system will contribute more
than the other TWO.
The 3 Energy Systems are not like TRAFFIC LIGHTS.
One does not switch off and another goes on.
44
Energy Systems Video Overview
45
The Role of Three Energy Systems During an
All-out Exercise Activity of Different Duration
46
Discussion Questions

• 1. What are the differences between the 3
  energy systems?
• 2. List one advantage and one disadvantage of
  each of the 3 energy systems.
• 3. Give an example of three activities or
  sports that use each of (a) the high energy
  phosphate system, (b) the anaerobic glycolytic
  system, and (c) the aerobic oxidative system as
  their primary source of energy (one sport for
  each energy system).
• 4. What is the most important source of fuel in
  the body for all types of energy production - a
  substance also known as the energy currency of
  the body?
• 5. Define ATP turnover and ATP resynthesis.
• 6. Describe how each of the three energy
  systems could be trained most efficiently.