1. What is ATP?
ATP is a chemical compound responsible for producing energy for work, which is provided by our diet.
When ATP is broken down, energy is released. i.e.
ATP → ADP + P ↓
ENERGY
There are small amounts of ATP stored in all muscle cells, but only enough to provide energy for a few seconds of work. Stored glycogen must be broken down to provide working muscles with a regular supply of ATP.
Glycogen comes from the food we eat (carbohydrates)

2. THE THREE ENERGY SYSTEMS
ATP – CP
Creatine Phosphate
(Anaerobic)
Oxygen is not present
1-15secs
Anaerobic glycolysis
Up to 3mins
Anaerobic = No air = No Oxygen
Aerobic = Air = Oxygen
Oxygen is present
Aerobic

3. Energy System
Duration
Source
ATP - CP
Immediate
1-15 seconds
CP in muscles
Anaerobic
Glycolysis
(lactic acid)
Short term
High intensity
Up to 3 minutes
Glycogen
Carbohydrates
Lactic acid produced
Aerobic
Long term
Low intensity
Unlimited
Carbohydrates and then fats
ATP replenished with o2

4. How do these energy systems inter-relate with one another?
2nd Gear (Anaerobic glycolysis)
+ Will keep you going for longer until you move into the next gear
1st Gear (ATP-CP)
+ Needed to get you going in a hurry
- You can’t go very far
3rd Gear (Aerobic)
+ Can continue for longer periods of time
- Can only run in this gear when the engine (heart) and radiator (lungs) are providing fuel (O2) to the car (body/muscles)

6. Energy systems in volleyball
What energy system(s) would be used in volleyball?
When are they used?

7. Long Term Effects of Exercise
Circulatory System
Increase in red blood cells
More oxygen to the working muscles for aerobic energy production
Resting heart rate and exercise heart rate decrease
Muscle around heart gets bigger, thicker stronger walls
Increase in heart volume
More blood pumped around the body per minute and more oxygen to muscles
Heart rate returns to normal sooner
More efficient at doing its job

8. Long Term Effects of Exercise
Respiratory System and Exercise
Respiratory muscles increase in strength (diaphragm/intercostal muscles)
Larger respiratory volume, more oxygen into lungs and into the blood
Increase in number and size of capillaries at alveoli = greater diffusion of oxygen and carbon dioxide
Breathing rate slows down

9. Long Term Effects of Exercise
Muscle
Muscles are larger are stronger
Can cope with additional stress put through them.
Receive more blood and therefore oxygen
Increase number of mitochondria = increase in rate of energy production
Increase in myoglobin = more oxygen stored in the muscles.
More flexible
Muscle memory