GR. 12 FITNESS ENERGY SYSTEMS Mr. Mackay

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

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

ANAEROBIC ALACTIC SYSTEM

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)

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.

ANAEROBIC LACTIC SYSTEM

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

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.

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

AEROBIC SYSTEM

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

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.

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.