VCE PE
Exam Preparation 2
Food To Energy
Food Fuels for Energy
1.
2.
3.
Carbohydrates (CHO) –
Preferred source of fuel during
exercise (Glycogen)
Fat – Concentrated fuel used
during rest and prolonged submaximal exercise.
Protein – Used for growth and
repair (Negligible use during
exercise)
VCE Physical Education - Unit 3
p.87
VCE Physical Education - Unit 3
Vitamins and Minerals
Vitamins assist: Point 3
• Red Blood Cell Production
• Tissue Repair
• Protein Synthesis
Minerals:
Iron: Absorbed in the blood and assists in the
production of haemoglobin
Calcium: Major component of bones and teeth.
Plays a part of muscle contraction and nerve
transmission
Sports Nutrition
Pre Event Meal (point 10-11)
• 1-4 hours prior to event
• Low GI foods (sustain energy)
• Low Fat and Protein: Ease digestion and avoid
stomach upset.
Post Event Meal
Restore Muscle glycogen as quickly as possible.
High GI foods (1g per 1kg of body weight within
30min of event). Can take 24hours to fully restore
glycogen following event.
Test Yourself
• Answer Multiple Choice Questions 1-9
• 1 C, 2 A, 3 D, 4 C, 5 A, 6 B, 7 A, 8 D, 9 C
Energy Systems
ATP-PC System
Characteristic
ATP-PC energy System
Also known as
PC System, CP system, phosphagen
system, alactic system
Fuel Source
Phospho Creatine (PC) or Creatine
Phosphate: same thing
Intensity of Activity
High 95+ % max Heart rate
Duration of system being dominant in
activity
Short (1-5 sec)
Peak power
2-4 Sec
ATP amount produced
Small : 0.7 ATP each PC molecule
Speed ATP produced
Explosive: relies on simple chemical
reactions
By-products
Inorganic Phosphates (Pi) ADP and AMP
Lactic Acid System
Characteristic
Lactic Acid System
Also known as
Anaerobic glycolysis, Lactacid system
Fuel Source
Glycogen
Intensity of Activity
High: 85+% of max HR
Duration of system being dominant in
activity
Intermediate duration 5-60 sec
Peak power
5-15 sec
ATP amount produced
Small 2-3 ATP each glucose molecule
Speed ATP produced
Fast: Longer chemical reactions than ATP
system
By-products
Lactic Acid, H+ ions, ADP
Aerobic System
Characteristic
Aerobic System
Also known as
Oxygen System, aerobic glycolysis
Fuel Source
Rest: FFA’s and CHO
Sub max activities: CHO, Fats when CHO
diminished, Protein: Extreme condition
Intensity of Activity
Rest
Sub Max activity: under 80% HR max
Duration of system being dominant in
activity
Long duration: 75 + sec
Peak power
1-1.5 min
ATP amount produced
Lots (endless)
CHO (38 ATP per glucose molecule)
Fats (441 ATP per triglyceride molecule
Speed ATP produced
Medium: Complex chemical reactions.
Fats slower to resynthesise ATP than fats
By-products
CO2, H2O Heat
Common Mistake
• The three energy systems
do not turn on and off like
a traffic light.
• They are always
interactive– the relative
contribution of each
system varies depending
on factors such as intensity,
type of activity and
duration.
VCE Physical Education - Unit 3
Interplay Between Energy Systems
All activities use some energy from all three systems.
The energy systems overlap – they never work independently.
It it’s the relative contribution of each system that varies.
VCE Physical Education - Unit 3
Anaerobic v Aerobic Contributions
VCE Physical Education - Unit 3
Key Points
• Accumulation of Hydrogen Ions: Hydrogen
Ions are a By-Product of the Lactic Acid System
(anaerobic glcolysis). H+ cause the muscle pH
to drop (become more acidic). This inhibits the
glycolytic enzymes and makes contractions
difficult.
Maximal Oxygen Uptake
• The maximum amount of oxygen per minute
that can be transported to, taken up and used
by the body for energy production. Measured
as mL/kg x min
Male
Female
Active young men 50.8
Active young women 45.4
AFL players 53.9
National Hockey 50.1
National Volleyball 56.4
National Volleyball 46.8
National Middle Dist 67
National Middle Dist 62.1
Long Dist 73.5
Test Yourself
• Answer Short Answer Question
Answer
a/ ATP-PC System
b/ 50%
c/ You can work at a percentage greater than
100% VO2 Max by working anaerobically.
d/ The test Percentage is different because it is
not at maximal intensity, unlike a 400m race.
Complete Multiple choice Questions
• Question 1-9
Answers 1 B, 2 D, 3A, 4 C, 5 C, 6 B, 7 A, 8A, 9C
Fatigue and Recovery
• Fatigue occurs when the body is unable to
function at it’s optimum level. Energy levels
are depleted.
Causes of Fatigue
Anaerobic Exercise
Aerobic Exercise
Fuel Depletion, ATP-PC, Creatine
Phosphate
Fuel Depletion: Glycogen
Metabolic By-Product Accumulation
Hydrogen Ions, Inorganic Phosphate and
ADP
Increase Body Temp
Dehydration
Effects of Fatigue
• Increased Body Temp: Blood is directed away
from the working muscles for cooling. Results
in reduced blood and oxygen to the working
muscle.
• Dehydration: Can result in impaired
performance (Blood flow away from working
muscles). Blood plasma volumes decrease. To
maintain Q, HR must increase.
RECOVERY
• Active Recovery (cool down): Low intensity
exercise to continue movement of blood from
working muscles (avoid blood pooling).
• Passive Recovery: Best to replenish PC stores
as more o2 available to replenish.
• Lactic Acid Breakdown: 50% removal in 30min
(halved with active recovery) 95% removal in
30min with an active recovery
Test Yourself
• Answer Multiple Choice 1-8
• Answers 1 D, 2 A, 3A, 4C, 5C, 6D, 7A, 8B
Short Answer Ques 9
a/ The athlete is restoring Muscle glycogen
b/ This should be eaten in the first 30 minute
following a race.
c/ To promote muscle repair and growth
d/ Best fuel source is High GI Carbs as the
provide a fuel source that can be used
immediately.