Energy is life. Our bodies are an intricately complex system built for the essential task of generating and dispersing energy. Believe it or not, you are in control of how much energy your system creates.

Regular exercise prompts your body to increase activity to match your needs. The inverse is also true. A sedentary lifestyle inhibits function to conserve its most vital resources.

But to truly understand energy, you have to look at the many cellular processes that are involved.

You need to look under the microscope to play witness. Every day, your body uses these seven mechanisms to drive you forward.

1. Mitochondria

You may remember these being referred to as the “powerhouses of the cell.”

Mitochondria have a role in nearly every mechanism and process within the human body. Every known function requires the energy generated within these microscopic “engines.”

Organs or tissues with high energy demand, like the heart and liver, often have a higher number of mitochondria per cell. According to the British Society for Cell Biology, mitochondria occupy roughly 40% of all cytoplasmic space within heart muscle cells. Likewise, each liver cell that helps your body filter out toxins and waste can play host to 1000-2000 mitochondria.

Without these organelles, we couldn’t move, breathe, eat, or even think. In short, your mitochondria make action possible.

2. The matrix

Each mitochondrion consists of two internal compartments: the mitochondrial matrix and an intermembrane space. A review published in Biochemistry states that the mitochondrial matrix is a gel-like material where cells hold and release stored energy.

The matrix is the primary working component of a mitochondrion. It functions as a storage space for the many enzymes, coenzymes, and proteins your body needs to generate energy. As mentioned above, it is also responsible for storing energy itself.

The matrix also helps mitochondria process their own genome to facilitate the replication, repair, and recombination of “bacterial and nuclear DNA.”

What does this mean?

Replication: During replication, DNA creates two identical copies of the original strand of DNA.

Repair: After replication, DNA works with enzymes to fix any resulting damage or errors in the genetic code. Some changes in replication, known as mutations, cannot be repaired and may be passed onto future generations.

Recombination: After DNA replicates, two independent strands of DNA are joined in a process called recombination.

The multiplication of mitochondrial DNA ultimately determines how many mitochondria live within each cell and how much energy will be expended for essential tasks. Energetically expensive tissue like muscle is known for having a high number of mitochondria per cell.

3. Fission

Fission, or the division of mitochondria, is one of the many ways your body maintains the ability to create energy. In short, it helps a cell generate the appropriate number of mitochondria for its task within the body.

Fission is a byproduct of a cell’s ancestry. The vestiges of single-cell organisms are the reason why mitochondria can divide and replicate independently of the host cell.

According to a review published in Science, fission also “contributes to quality control” by regulating cell death during periods of stress. The article continues, “mitochondrial fission... play[s] critical roles in maintaining functional mitochondria when cells experience metabolic or environmental stresses.” Stressors like sun exposure or sleep deprivation can cause mitochondrial death and dysfunction. Fission helps clear away damaged and dead material, ensuring energy is spent on live tissue.

Without fission to maintain the creation and destruction of mitochondria, cells can’t develop the working parts they need to energize their function adequately.

4. Adenosine triphosphate (ATP)

This molecule IS energy. When you’re tired, you don’t need more caffeine. You need more ATP.

ATP synthesis is like a highly advanced, microscopic game of hot potato. Our cells toss electrons from the carbs, fats, and proteins we consume over to oxygen molecules. Once these electrons are accepted by oxygen, it then picks up protons to form water—completing the process we know as ATP production.

According to a review published in Purinergic Signal, oxidation allows ATP to be stored in the bonds between molecules.

Once these steps are completed, cells throughout the body use ATP to power movement, cognition, and all physiological processes.

5. Nicotinamide adenine dinucleotide (NAD+)

NAD+ (nicotinamide adenine dinucleotide) is found in every living human cell. NAD+ is a molecule that attaches itself to an enzyme to trigger and accelerate chemical reactions, also known as a coenzyme.

NAD+ supports many cellular processes. It elevates cellular energy and maintains defense and repair mechanisms within the cell.

If mitochondria are the cell’s engines, NAD+ are the wires that connect the engine parts. Without this vital molecule, many of our biological functions would be rendered useless. From oral supplementation to dietary changes, there are several ways to increase NAD+ production.

6. Citric acid cycle

According to Biochemistry, the citric acid cycle (also known as the Krebs Cycle) “is the central metabolic hub of the cell.”

The citric acid cycle uses a series of chemical reactions to release energy, or ATP, stored in the matrix. Biochemistry shows, “the cycle is also an important source of precursors, not only for the storage forms of fuels but also for the building blocks of many other molecules such as amino acids.”

The building blocks of energy, known as precursors, are processed during this cycle.

When a glucose molecule enters a mitochondrion, it undergoes a series of transformations where it gradually loses electrons. During this process, NAD+ is used to accept electrons and help produce energy in the form of ATP.

The citric acid cycle is deeply technical and may be difficult for the layperson to understand. So, this is your takeaway: Within your mitochondria, molecules from food are turned into energy.

7. Cellular respiration

This complicated multi-step process uses ATP, the Citric Acid Cycle, and NAD+ to continually break down sugar from our food and drinks and turn it into the energy we need to stay healthy.

Despite its bad reputation in diet circles, sugar has a genuine energetic value to the human body. To obtain sugars while eating clean, snack on sweet fruits like pears and green apples. The healthy sugars and fibers will provide your cells with better energy.

Why is it important to know how your body creates energy?

There are days where you sleep eight hours, have a balanced breakfast and a cup (or two) of coffee, and still feel drained before the day even starts.

All too often, the source of your exhaustion lies in your cells.

Impairment of any one of the seven mechanisms detailed above can result in noticeable fatigue. If you’re looking for better energy, don’t settle for quick fixes. Energy creation begins and ends at the cellular level, and there are ways to elevate productivity from within.

Managing the stressors that inhibit mitochondrial function can maintain your vital energy. Limiting sun exposure or dehydration can help mitochondria thrive and reduce the energy spent on repairing damaged cells.

Next time you feel a wave of unexplained exhaustion, consider your smallest parts. Equipped with newfound knowledge and solutions, you can work to combat fatigue cells-first.