1. Energy systems.

2. PHYSIOLOGICAL REQUIREMENTS OF PHYSICAL ACTIVITY
Foods
Fuel and
Energy Systems

3. Where does this energy come from?
A Maria Sharapova serve takes 1-2 seconds to perform. It’s fast & explosive. She might do this hundreds of time over a game. Plus she has to run fwd, bkwd and sideways for 1-2 hours. Her Muscles requires ENERGY to do this.
Where does this energy come from?

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 body’s 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 + Energy
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, soooo….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
Alactacid system
Creatine phosphate system
Phosphagen system.
The Lactic Acid Systems
Anaerobic glycolysis system
Lactacid system
Aerobic System
Aerobic Glycolysis

15. ATP –PC system 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.

16. 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.

17. For activity lasting:
0-10 SEC
ATP-PC SYSTEM
10-30/40 SEC
LACTIC ACID SYSTEM
30 + SEC- 2MINS
AEROBIC SYSTEM

18. 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…..

19. Summary
Each ATP molecule is made up of an adenosine part and three phosphate groups. When 1 mole (1) of ATP is broken down, 7 to 12 Kcal (2) of energy is released.
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.

20. Summary Cont…
However, the total amount of PC stored in the human body is also extremely limited. There are altogether 450 to 510 mM PC, or 4.5 to 5.1 Kcal of energy in the human body. 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.

21. 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).

22. LACTIC ACID SYSTEM Need Oxygen to do this properly
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

23. Used in longer, sub-max activities. Long run, swim, cycle.
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!!!!

24. BUT, need 3 minutes rest to get all CP back!
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.

25. All 3 turn on at once no matter what the activity.
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.