PE food fuels and energy system Unit 1 AOS 3

Where does energy come from 

• ATP = energy 

• ATP is the major source of energy that is stored in our muscles  

• It exists only in small amounts  

• By breaking the bond between the second and third phosphate molecule we realse large amounts of energy that can be used for muscular movement  

Resynthesis of ATP  

• ATP is produced by resynthesis (rebuilding) by joining the free phosphate (pi) back to ADP (adenosine +Pi+Pi) 

• The factors that resynthesis of ATP depend on are:  

• Duration  

• Intensity  

• If oxygen is present  

• Availability of chemical/food fuels  

2 types of food fuels are required for ATP resynthesis  

• Chemical fuels  

• Food fuels  

• Phosphate creatine (PC) chemical fuel  

Food fuels  

• A food fuel is different types of food that are broken down to produce energy  

• Carbohydrates  

• Fats 

• Protein  

Carbohydrates  

• Once digested it is broken down into glucose  

• Stored as glycogen  

• Carbs are the preferred fuels source due to  

• Their easy access (as they are stored in muscle cells) 

• Their plentiful supply  

• They can be used under both aerobic and anaerobic conditions  

• 55-60% of diet come from carbs  

• It is preferd over fat as it requires less oxygen to be able to produce the same amount of energy 

Glycaemic index 

• A ranking of carbohydrates on a scale from 0-100 according to the extent to which they raise blood sugar levels after eating 

• Low GI: less than 55, slowly digested and absorbed gradual rises blood sugar provides an ongoing energy source for endurance events  

• Examples: bread, rice, pasta  

• High GI: more than 70, rapidly digested and absorbed, significantly fluctuations in blood sugar levels, most useful as a dietary recovery strategy  

• Examples, Lollie snakes, fruits, honey  

Fats  

• Fats are broken down and stored as triglycerides in muscles  

• Fats are  the preferd source at rest and during prolonged submaximal exercise  

• Fats are found in foods such as nuts, oil, dairy food etc. 

Protein  

• Protein are found in high concentration lentils and red meat  

• Proteins are the building blocks of tissues vitality important in muscle growth and repair  

• Broken downm into amino acids  

• Rarely used for source of energy  

• High amounts of oxygen are required to break them down  

• Amino acids are only use din extreme circumstances  

ATP-PC 

Rate = how fast  

Yield = how much  

How the ATP-PC system works for exercise  

• Breaking down the stored ATP to ADP  

• PC stored in muscle breaks down anaerobically  

• Fastest energy system dominant provider of ATP for the first 5-10 seconds  

Advantages and disadvantage of the ATP-PC system  

Anaerobic glycolysis system  

• The anaerobic glycolysis system is also anaerobic nature and produces atp through the breakdown of carbohydrates stored as glycogen in the muscles  

• It produces ATP in greater amounts that the ATP-PC  system but at a  slower rate 

• It also supplies energy from the start of high intesity exercise  

• Predominant energy system for high intensity activities approx. 60 seconds 

• It does not require oxygen fatiguing by- products (build up of hydrogen ions)  

How does the anaerobic glycolysis  system works  

• Stored glycogen in the muscle is converted into glucose  

• contributes to making ATP when 

•  intensity increases (85%-95% of max HR) 

Aerobic energy system 

• ATP is produced in the presence of oxygen  

• Preferred fuel source is glycogen it can also utilize fats  

• Can use protein under extreme circumstances  

• Produces ATP at the slowest rate  

• Produce greatest amount  

• Predominant supplier of energy during long duration, sub-maximal activity and during long duration high intensity activity lasting more than a minute  

• Does not have any fatigue causing by products  

How aerobic system works  

• Complex chemical reactions occur & energy is produced aerobically  

• Oxygen allows for a more complete breakdown of glucose  

Rate of ATP Production  

• Dependent on the complexity of the chemical reaction required  

• ATP-PC system provides ATP rapidly as it is a simple chemical reaction  

• Anaerobic glycolysis slower rate due to the  more complicated chemical reactions  

• Aerobic energy system produces ATP at the slowest rate of all three systems due to the number and complex nature of its chemicals reaction