1. GR. 12 FITNESS
ENERGY SYSTEMS
Mr. Mackay

2. MUSCULAR SYSTEM
Energy in the human body is derived from the breakdown of macronutrients like: carbohydrates, fats, and proteins.
The end result of this breakdown is the production of ATP molecules.
ATP provides energy for body functions.
Carbohydrates
Fats
Proteins
ATP
Muscular Work
Digesting Food
Thermoregulation
Breakdown of
Energy currency
Biochemical processes

3. ATP Breakdown ATP Resynthesis ATP ADP + Energy + P + ATP ADP Energy +
H2O +
Energy + P +
ATP Resynthesis
ATP
ADP
Energy + P +

4. ANAEROBIC ALACTIC SYSTEM

5. ANAEROBIC ALACTIC SYSTEM
Primary energy source:
Duration of activity:
Sporting events:
Advantages:
Limiting factors:
Stored ATP, CP
7-12 s
Weight lifting, high jump, long jump, 100m run, 25m swim
Produce very large amount of energy in a short amount of time
Initial concentration of high energy phosphates (ATP, PC)

6. TRAINING Sprint training: Interval training: No change in ATP stores.
20% increase in CP (creatine phosphate) stores.
No change in ATP stores.
Increase in ATP function (ATP -> ADP+P)
Increase in CP (creatine phosphate) and allows ATP resynthesis.
Sprint training:
Increase in CP stores up to 40%.
100% increase in resting ATP stores.

7. ANAEROBIC LACTIC SYSTEM

8. ANAEROBIC LACTIC SYSTEM
Primary energy source:
Duration of activity:
Sporting events:
Advantages:
Limiting factors:
Stored glycogen, blood glucose
12 s – 3 min
Lactic acid build up, H+ ions build up (decrease of pH)
800m run, 200m swim, downhill ski racing, 1500 speed skating
Ability to produce energy under conditions of inadequate oxygen

9. Lactic Acid 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.

10. TRAINING
Rate of lactic acid accumulation is decreased in the trained individual.
This rate can be decreased by:
Reducing the rate of lactate production.
Increasing the rate of lactate elimination

11. AEROBIC SYSTEM

12. AEROBIC SYSTEM Primary energy source: Duration of activity:
Sporting events:
Advantages:
Limiting factors:
Glycogen, glucose, fats, proteins
> 3 min
Lung function, max.blood flow, oxygen availability, excess. energy demands
Walking, jogging, swimming,
walking up stairs
Large output of energy over a long
period of time, removal of lactic acid

13. AEROBIC SYSTEM The most important energy system in the human body.
Blood lactate levels remain relatively low.
Primary source of energy (70-95%) for exercise lasting longer than 3 minutes provided that:
Working muscles have sufficient mitochondria to meet energy requirements.
Sufficient oxygen is supplied to the mitochondria.
Enzymes or intermediate products do not limit the Kreb’s cycle.

14. TRAINING
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.
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.