How Red Light Stimulates Cellular Respiration and Boosts Energy Production
Natural light powers almost all life on earth, and humans are no exception. We’re powerful animals with billions of cells, and each one of them needs energy to do their job. We create that energy every second in a process called cellular respiration, and red and near infrared (NIR) light plays a major role.
Red and NIR light includes a specific range of wavelengths within the natural light spectrum that’s been studied extensively and found to be extremely beneficial at the cellular level, resulting in numerous clinically-proven benefits like the reduction of pain & inflammation, skin rejuvenation, and muscle recovery. 
This article provides a summary of the science behind the energy-producing cellular respiration process, and explains the fascinating role red and NIR light plays at the intra-cellular level. The many published studies on the subject make it clear that the story of energy, red light, and cellular respiration begins in our mitochondria.
What are Mitochondria?
Mitochondria are double-membrane structures in our cells responsible for cell signaling, steroid synthesis, cell apoptosis, and cellular energy.  Chances are you had a biology test at some point where you had to know that mitochondria are referred to as the “powerhouses of the cell". They’re often described in this way because they facilitate the production of adenosine triphosphate (ATP), usually referred to as the “energy currency of life”.
Mitochondria are unique, with their own ribosomes and DNA. They’re typically round or oval in shape and range from .5-10 microns in size, so we can’t physically see them, but they affect everything we do. There can be as few as 1-2 mitochondria per cell or as many as thousands, it all depends on the energy needed for that cell to function. [3,4]
What is Adenosine Triphosphate (ATP)?
ATP is a high-energy molecule whose sole function is to create and store energy in our cells. Our body uses it to do pretty much everything. Some cells (like muscle cells) require a lot more ATP than others because of the intense demands placed on them. Interestingly, humans recycle their own body weight equivalent in ATP every single day. 
How is ATP Created?
ATP is created using cellular respiration, one of the leanest and most efficient metabolic pathways on earth. This process involves using several key ingredients: the oxygen we breathe, the water we drink, and the food we eat.
Before we get microscopic and explain cellular respiration, we need to quickly touch on a few concepts, since not everyone remembers those high school science quizzes.
Here’s your cheat sheet:
- Charge: Electrons (-) and protons (+) are the charges of life as we know it. Everything that exists in our universe operates using a negative and positive charge. When a compound sheds electrons, it’s called oxidation. When it gains electrons, it’s called reduction (because more electrons means more negative charge).
- Coenzymes: The cargo trucks of cell respiration, these small molecular compounds transport protons and electrons into the mitochondria. Nicotinamide Adenine Dinucleotide (NAD+) & Flavin Adenine Dinucleotide (FAD) are the two crucial coenzyme carriers in cellular respiration.
- Hydrogen: Sometimes even the most abundant chemical substance in the universe needs an introduction. Hydrogen ions (H+) have a positive charge and play a key role in cellular respiration. When NAD+ or FAD pick up electrons, they also pick up H+ ions, which converts them into a reduced state, resulting in NADH or FADH2 (also coenzymes). Your key takeaway on hydrogen should be that it’s needed to complete the 4-stage process of cellular respiration; without it, we can’t make ATP.
4 Stages of Cellular Respiration
ATP can be created two ways, aerobic (with oxygen) or anaerobic (without oxygen), but aerobic is much more common and beneficial, because it produces more energy.  Aerobic cellular respiration has four stages. In the first two stages, our bodies strip nutrients from our food, turning them into usable fuel in the form of carbon compounds.
- Glycolysis: The basic metabolic pathway in all organisms where food is broken down into chemical compounds called pyruvate.
- Pyruvate Oxidation: Pyruvate is broken down (oxidized) into Acetyl CoA. Remember, when anything is oxidized, it means that it loses its electrons. Those electrons are picked up by NAD+, which grabs a hydrogen ion and forms NADH. Carbon dioxide is generated as waste and we are off to stage 3. 
In steps 3 & 4, the aforementioned carbon compounds are converted into the vast majority of energy used by aerobic cells (over 95% of cell energy in humans is produced through this process).
- Citric Acid Cycle: This is the vital metabolic core process of the cell. The main function of the citric acid cycle is oxidation, where high-energy electrons and protons are harvested from the carbon compound (acetyl-CoA) created during the previous stage. This creates electron and proton carriers (coenzymes) called NADH and FADH2. Electrons and protons have to be oxidized into these individual coenzyme units to create ATP during the final stage of cellular respiration. This is a highly efficient and important process because a limited number of molecules generate large amounts of NADH and FADH2. 
- Oxidative Phosphorylation: The process starts when electron carriers NADH and FADH2 unload electrons slowly into the electron transport chain (ETC), which creates energy. As electrons flow down the ETC, they meet up with oxygen to form water and CO2 as byproducts. At the same time, hydrogen ions (H+) are released as NADH & FADH2 are oxidized. H+ ions are then pumped upstream through protein complexes I, III, & IV into the intermembrane, where they build up. As they begin to gather, potential energy is created in the form of a gradient. Those ions then flow downstream through an enzyme called ATP synthase, where they re-enter the matrix as ATP molecules.
When cellular respiration is broken down to the atomic level, it becomes clear why it all boils down to electrons (e-) and protons (H+) for ATP production. 
How Does Red and NIR Light Enhance ATP Production?
The short answer is: by breaking up the major roadblock to ATP and water production, which is harmful excess nitric oxide. During the creation of ATP synthase, nitric oxide competes with oxygen, which stops the eventual production of ATP. This also increases oxidative stress, which can lead to cellular death. The photons in red and NIR light excite electrons, which helps break up nitric oxide bonds so H+ ions can move through the process more effectively, resulting in more ATP energy that powers your cells and your entire body.
Conclusion: Red Light Boosts Cellular Energy Production
The more efficiently your cells create ATP energy through cellular respiration, the better your body feels and performs. Red and NIR light stimulates mitochondria and works against nitric oxide & oxidative stress that weakens our cells and slows us down.
Now, with 21st century technology and science, it’s safe, effective, and affordable to harness the power of red light!
Scientific Sources and Medical References: