• 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)

• ATP provides energy necessary for body function.

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

• 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.

• The 3 energy systems are: 1 ) ATP-PC System (Anaerobic without oxygen) 2) Anaerobic Glycolysis (Anaerobic without oxygen) 3) Aerobic (Aerobic with oxygen)

• 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 used for short bursts of exercise such as a 100 meter sprint.

and is • 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  ADP + “energy” (2-3 secs) • ADP + CP  ATP + C (4-10 secs)

Primary Energy Source Duration of Activity Sporting Events Advantages Limiting Factors Stored ATP, CP Up to 10 sec 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)

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

Bicep Curl 1RM (repetition maximum)

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

Primary Energy Source Duration of Activity Sportng Events Advantages Limiting Factors Stored glycogen, blood glucose 10 secs – 2 min 200m swim, 400 min sprint, Fast break in basketball etc.

Ability to produce energy under conditions of inadequate oxygen Lactic acid build up, H+ ions build up (decrease of pH)

Glycogen Glucose Energy ATP ADP + Free Phosphate Pyruvic Acid (no oxygen) Lactic Acid + hydrogen ion Energy for Muscles

• 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.

• • To test this system in class we use muscle endurance exercises Pushups, Situps, and Lunges for 2 minutes.

• 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

Primary Energy Source Duration of Activity Sportng Events Advantages Limiting Factors Glycogen, Carbohydrates, fats, proteins > 2 min Walking, Marathons, triathlons, cross country skiing, AFL midfielder, Basketball game, rowing 2000m Large output of energy over a long period of time, removal of lactic acid Lactate and hydrogen ion accumulation, overheating, glucose and glycogen stores.

Glycogen Glucose Pyruvic Acid (no oxygen) Fats ( and O2) + Protein (emergen cy ATP source) Citric acid cycle Hydrogen ions Electron transport chain Energy ATP for Muscles ATP for Muscles ATP ADP + Free Phosphate Energy for Muscles

• • To test this system we use cardiovascular endurance perform the 12 minute walk run and record the distance covered in 12 minutes.