This chapter is a brief explanation of exactly how the body produces energy.


Weight lighting? / Boxing? / Distance running?

The body needs a continuous supply of energy, whether the energy is needed for lifting weights, walking, thinking or even texting.

Before we move onto the ATP diagram below, here is a summary of the essential ingredients you need to produce energy.

Phosphate is an electrically charged particle in your blood that participates in energy production. It consists of the mineral phosphorus and oxygen. When ingesting foods rich in phosphorous like beans, cereals, chicken, nuts, dairy products, fish, and eggs, phosphorous is absorbed in your body in the small intestine. Phosphorus is then combined with oxygen to form phosphate.

Adenine is a purine nucleobase and is one of the four nucleobases in the nucleic acids of DNA and is an essential component of the energy production. 

Ribose is a naturally occurring sugar molecule. It is made from blood glucose and is known to enhance energy, support the heart and skin.

Adenosine is adenine bound to a ribcose sugar. 

Adenosine Triphosphate is adenosine plus the addition of 3 phosphates.


ATP is like the energy currency for the body. It is a molecule that is stored in the body and when broken down it enables muscle contraction.

ADENOSINE TRIPHOSPHATE   Adenosine Triphosphate (Tri =3)

ATP and ADP. Absorb and Release energy into cell.


As already mentioned ATP is Adenosine plus 3 phosphates, attached by a chemical bond and it is these chemical bonds that store the energy necessary for a muscle contraction … so when you need some muscle action the ATP has a phosphate broken off and it is this ‘breaking off’ of the phosphate from the bond that gives you that energy!

But now the ATP is only left with 2 phosphates and is now known as

Adenosine Duophosphate  (duo=2)  in short ADP

If you want some more energy, you need to get a phosphate back in there to recreate the ATP, as this is your energy source! This whole process of getting the phosphate back into the system is called Resynthesis.

The body has 3 different pathways it can take to do this depending on the demand, the fuel source and does it have oxygen to work with?

ATP – PC Pathway  example Weightlifting

This system is anaerobic, which means it does not use oxygen and its fuel source is Creatine Phosphate which is stored in the muscle.

This energy force only lasts 6 – 10 seconds and it needs 2-3 minutes to properly recover. This is ideal for EXPLOSIVE power as the Creatine Phosphate is in the muscle, readily available so it’s a simple reaction that happens fast and has very little negative by-products. There isn’t much creatine phosphate in the muscle so this system can tire quite quickly.

This system can only produce 1 ATP at a time, so this is why is doesn’t last long.

The Lactate System … example Boxing

The lactate system, also called the anaerobic glycolysis system, produces energy from muscle glycogen – the storage form of glucose. Glycolysis, (the breakdown of glycogen into glucose), can occur in the presence or absence of oxygen. In the case of without oxygen, the system’s fuel source is glucose. This glucose, which is a simple sugar, can be found in the bloodstream, liver, and muscles. When the glucose is broken down, the energy that is released from this ‘breakdown’ is what is used to RESYTHISIS and recreate ATP, but the by- product is Lactic Acid.

This energy lasts longer than ATP- PC and this can last up to 2 minutes, but the recovery takes longer than the ATP – PC Pathway.

This system can create up to 3 ATPs.

The Aerobic System …example Distance Running

This is the most complicated system.

This system produces ATP as energy and is released from the breakdown of nutrients such as glucose and fatty acids in the presence of oxygen. In most cases we have a decent amount of glucose and fat so we can produce a large amount of energy that can last quite a while and has simple by-products like carbon dioxide and water.

This pathway can generate up to 29 – 34 new ATPs!

Summary of energy systems

Energy System - 1