MITOCHONDRIA

“ The Powerhouse of The Cell ”

BY AMJAD SALEH Accredited Exercise Physiologist

Mitochondria are the power generators for all our cells and are within all of our cells. They convert oxygen and nutrients into ATP (the energy currency our body needs to function). Without Mitochondria (aerobic energy system), our body would rely on anaerobic (non-oxygen) energy systems to supply our energy, which are much less efficient. Mitochondria produce 36 ATP in one cycle, while anaerobic energy systems would provide a measly 2 ATP! Without Mitochondria, humans and complex animals would not be able to produce the large amounts of energy required to survive.

 Mitochondria generate energy (ATP) by breaking down sugars, fats and other chemicals (i.e. pyruvate) with the assistance of molecular oxygen. Mitochondria are also involved in other tasks such as communication between cells and cell death. The number of mitochondria in cells vary widely depending on the type of cell. For e.g. a red blood cell has no mitochondria but liver cells can have more than 2000.

ATP is produced in the mitochondria via a complex process called the Kreb’s cycle. The human body relies on 3 energy systems for any function;

  1. ATP-Pcr (Anaerobic, explosive energy)

  2. Glycolytic (Anaerobic, short – medium term energy)

  3. Kreb’s Cycle (Aerobic, long term energy)


However, our body will always get a certain percentage of its energy from the aerobic system depending on the intensity and duration of a task. The aerobic energy system will be predominantly used in lower intensity and longer duration activities such as walking, where muscular contractions aren’t demanding a rapid supply of energy. As humans, the majority of our daily activities involve low intensity, aerobic respiration, and from this you can see how important properly functioning mitochondria are. Mitochondrial dysfunction has been implicated in multiple human diseases such as;

  • Cardiac dysfunction

  • Autism

  • Alzheimer’s

  • Parkinson’s Disease

  • Bipolar, Diabetes

  • Chronic Fatigue Syndrome, and the list goes on.


The good news is that mitochondria are highly adaptable - we can improve the function of mitochondria and the number of mitochondria we have with Aerobic Exercise.

Aerobic Exercise generally refers to “light to moderate” intensity activity that can be maintained for extended periods of time (> 10 min). Examples include long distance running, jogging, swimming, cycling and rowing. Although, high intensity interval training has also been shown to improve aerobic capacity and this could be explained by the fact that even at extremely high intensities our bodies still use 40 -50 % aerobic (oxygen) energy, therefore using the mitochondria. Aerobic exercise has been shown to increase the number of mitochondria by up to 50%, not only increasing the number of mitochondria but also increasing the size and volume of our mitochondria to allow a greater capacity of energy production. Aerobic exercise has also been shown to repair and remove damaged mitochondria. However, you must be diligent with your exercise regime as the benefits obtained to your mitochondria return to normal levels within a month of not training.

Amjad Saleh