ENERGY SYSTEMS

FOOD TO FUEL• Energy in the human body come from the

breakdown of nutrients like carbohydrates, proteins and fats

Food = Energy (ATP)

• The end result of this breakdown is the production energy in the form of Adenosine triphosphate (ATP)

ENERGY PATHWAYS• ATP provides energy necessary for body

function.

• Because the body can not easily store ATP it is necessary to continually create ATP during exercise.

ENERGY PATHWAYS• In general, the two major ways the body converts

nutrients to energy are:

• Aerobic metabolism (with oxygen) • Anaerobic metabolism (without oxygen)

• There is a total of 3 Energy systems that interplay to supply the fuel needed for exercise, with the intensity and duration of the exercise determining which method gets used when.

ENERGY SYSTEMS• The 3 energy systems are:

1) ATP-PC System (Anaerobic without oxygen)

2) Anaerobic Glycolysis (Anaerobic without oxygen)

3) Aerobic (Aerobic with oxygen)

ATP-CP SYSTEM• The ATP-CP energy pathway (sometimes called the phosphate system) uses

ATP CP stores directly.

• This pathway doesn't require any oxygen to create ATP.

• When is it used? supplies about 10 seconds worth of energy and is used for short bursts of exercise such as a 100 meter sprint.

• It first uses up any ATP stored in the muscle (about 2-3 seconds worth) and then it uses creatine phosphate (CP) to resynthesize ATP until the CP runs out (another 6-8 seconds).

• After the ATP and CP are used the body will move on to either aerobic or anaerobic metabolism (glycolysis) to continue to create ATP to fuel exercise.

ATP-PC System Chemical Process

• ATP ADP + “energy” (2-3 secs)

• ADP + CP ATP + C (4-10 secs)

ATP-CP SYSTEM

Primary Energy Source Stored ATP, CP

Duration of Activity Up to 10 sec

Sporting Events Weight lifting, high jump, long jump, 100m run, 25m swim

Advantages Produce very large amount of energy in a short amount of time

Limiting Factors Initial concentration of high energy phosphates (ATP, PC)

Put it to the test….

• To test the ATP-CP system we use muscular power.

• Bicep Curl 1RM (repetition maximum)

ANAEROBIC GLYCOLYSIS• The anaerobic energy pathway, or glycolysis, creates ATP

exclusively from carbohydrates

• Creates this ATP without the need of oxygen

• Lactic acid and Hydrogen ions are by-product of this system.

• When is it used? Anaerobic glycolysis produces energy for short, high- intensity bursts of activity lasting no more than several minutes before the lactic acid build-up reaches a threshold known as the lactate threshold and muscle pain, burning and fatigue make it difficult to maintain such intensity.

ANAEROBIC GLYCOLYSIS

Primary Energy Source Stored glycogen, blood glucose

Duration of Activity 10 secs – 2 min

Sportng Events 200m swim, 400 min sprint, Fast break in basketball etc.

Advantages Ability to produce energy under conditions of inadequate oxygen

Limiting Factors Lactic acid build up, H+ ions build up (decrease of pH)

Anaerobic Chemical Process

LACTATE THRESHOLD

• Lactic acid threshold is the common term used when the level of lactate acid nad H+ within the bloodstream and working muscles is above which an individual cannot continue to physically exersise at a desired level.

• Trained athletes can increase their tolerance to LA accumulation and are able to continue effective performance or training with much higher lactate and H+ levels in their working muscles and circulatory system.

Put it to the Test….

• To test this system in class we use muscle endurance exercises

• Pushups, Situps, and Lunges for 2 minutes.

AEROBIC SYSTEM• Aerobic system fuels most of the energy needed for long duration activity.

• It uses oxygen to convert nutrients to ATP.

• This system is a bit slower than the anaerobic.

• Relies on the circulatory system to transport oxygen to the working muscles before it creates ATP.

• When is it used? Endurance events, less intense activities, that last long periods of time.

• This system creates 38 molecules of ATP from 1 molecule of gluscose

AEROBIC SYSTEM

Primary Energy Source Glycogen, Carbohydrates, fats, proteins

Duration of Activity > 2 min

Sportng Events Walking, Marathons, triathlons, cross country skiing, AFL midfielder, Basketball game, rowing 2000m

Advantages Large output of energy over a long period of time, removal of lactic acid

Limiting Factors Lactate and hydrogen ion accumulation, overheating, glucose and glycogen stores.

Aerobic System Chemical Process

ATP for

Muscles

Fats ( and O2)

+Protein

(emergency ATP source) ATP

for Muscles

Put it to the test…..

• To test this system we use cardiovascular endurance

• perform the 12 minute walk run and record the distance covered in 12 minutes.

ENERGY SYSTEM FOR SELECTED SPORTS