1. Achievement Standard 2.3
Demonstrate understanding of the application of biophysical principles to training for physical activity.

2. COMPONENTS OF FITNESS
There are several ways that we can classify fitness because fitness is specific to the requirements of each individual.
We usually think of ‘being fit’ as being aerobically fit, but does our Olympic Weightlifter or 100 meter sprinter need to be able to run a Marathon to be successful in their sport?
No, therefore the requirements to succeed in their sports are very different.
What does fitness mean to you. Write down what your definition of fitness is and how do you judge if you are fit or not?

3. We classify our Components Fitness into 2 categories
Health –related fitness
Skill-related fitness
Health-related components directly affect our health and well being, while Skill-related components tend to affect our performance level in our chosen sports rather than our health.

4. Health –related fitness
Cardio-respiratory Endurance
Muscular Strength
Muscular Endurance
Flexibility
Body Composition

5. Skill-related components
Power
Balance
Co-ordination
Speed
Agility
Reaction time

6. Fitness testing Endurance Muscular strength Muscular Endurance
An understanding of these components is vital for sport. After analysing the requirements for your sport you can then tailor a programme that caters for those components. You would then test the fitness levels for the different components. Think of tests that would cover the following components
Endurance
Muscular strength
Muscular Endurance
Flexibility
Power
Agility
Speed

7. ENERGY SYSTEMS
Energy for muscular activity and other biological work comes from the breakdown of adenosine triphosphate (ATP).
ATP loses one phosphate molecule and breaks down to Adenosine diphosphate (ADP). Energy is then released.
ATP storage is limited. The body must regenerate its ATP as quickly as it is broken down. This regeneration connects the ADP and a Phosphate together again to create ATP again.
There are three energy systems for this:
ATP-PC system
Lactic acid system
Oxygen (or aerobic or alactacid) system

8. The ATP-CP System
This is used for high intensity exercise for tasks of approx secs (eg. sprinter).
This system uses a chemical fuel reserve, Creatine Phosphate, which is stored in the muscle.
This process is anaerobic (meaning it does not require the use of oxygen for it to work).
CP is broken down into Creatine and Phosphate and the energy released from the breakdown is used to combine ADP and Pi to produce ATP.

9. The Lactic Acid System
This is used for high intensity exercise for tasks of approx. 30 secs-3 mins (eg. 400m runner).
The lactic acid system uses the anaerobic breakdown of glycogen which occurs in the cell.
Glycogen is the form that carbohydrate is stored in the body (in the liver and in muscles). This process does not require oxygen.
Lactic acid build-up occurs during this phase. This causes fatigue.

10. The Aerobic System
Used for low intensity exercise that is longer than 2 mins (eg. Marathon runner).
The Aerobic system produces its energy by utilising oxygen.
This system uses glucose from the muscles. If glucose runs out, fatty acids are used. Finally if fat stores are depleted, protein is used.
The results are the regeneration of ATP molecules and the production of by-products - water and carbon dioxide.

11. Summary of Energy Systems
ATP-CP System Lactic Acid System Aerobic System
Anaerobic Anaerobic Aerobic
Very rapid Rapid Slow
Chemical: CP Food: glycogen Food: CHO, Fat, Protein
Very limited ATP Limited ATP Unlimited ATP
Muscular stores Lactic Acid causes No fatiguing limited fatigue by-products
Explosive, sprint 30 sec to 3 min Endurance
100m 400m Marathon