1. Magnesium fuels muscles:
The main reason we eat fat and carbs is because our cells convert them into energy molecules called ATP: Adenosine Triphosphate. Every stage of ATP generation requires magnesium.[1,11] The first stage is when cells (including muscle cells) absorb fats and carbs from our bloodstream:
Magnesium helps muscles absorb fuel
Carbs (glucose): The hormone insulin lets muscles absorb carbs. It’s made via protein synthesis (which requires magnesium)[12-16] by beta cells that function better with magnesium. Insulin receptors also need magnesium.[18-22] All this explains why magnesium supplements improve our cells’ sensitivity to insulin, which is desired by all athletes.
Fats (fatty acids): When we burn body fat, the hormones glucagon and growth hormone force fat cells to release their stored fatty acids so that muscle cells can then absorb and use them for energy. These two fat-liberating hormones are made via protein synthesis – a process which requires magnesium.[12-16] Fats then require special transporters to enter cells. They are also made via magnesium-dependent protein synthesis.
Magnesium converts fat & carbs into energy
Muscle cells convert glucose and fatty acids into energy in three sequential phases. The first phase happens in the cell, and the second and third happen inside the cell’s mitochondria: the energy factories that produce 90% of a healthy cell’s energy.[25,26]
PHASE 1: In the first phase, glucose and fatty acids each undergo their own multi-step process that breaks them down into smaller molecules called Acetyl-CoA:
Glucose undergoes glycolysis. Seven of the ten steps in glycolysis need magnesium. Because each step in glycolysis needs the prior step to occur first, glycolysis is impossible without magnesium.
Fatty acids undergo beta oxidation. Each step again depends on the previous, and the entry step needs magnesium, which makes beta-oxidation dependent on magnesium.
PHASE 2: The smaller Acetyl-CoA molecules now enter our mitochondria for phase 2:
The citric acid cycle is the first of these two phases. It has 7 steps, all of which cannot happen without the prior step happening first. Four of these steps required enzymes that need magnesium, making this entire process impossible to complete without magnesium. The completion of the citric acid cycle creates even smaller molecules called electron carriers, which enter the final and most important phase of ATP (energy) generation, where most of the ATP is made:
PHASE 3: Oxidative phosphorylation, is the last phase of ATP production where mitochondria use oxygen and electrons to create large amounts of ATP. The fourth step that uses the cytochrome c oxidase enzyme, requires magnesium. Magnesium also plays a crucial role In the final step where the enzyme ATP synthase finally produces the ATP molecules.
Simply put, without magnesium we can’t make energy. This explains why metabolic disorders like diabetes (whose main problem is low cellular energy production) are associated with low magnesium intake.[33,34]
Magnesium is ATP energy!
In addition to converting fat and carbs into ATP, magnesium also makes up an actual physical component of the ATP molecule, which is why the molecule is actually called Mg-ATP.[35,36] This is why magnesium is involved in all biochemical processes involving ATP  and why ATP is biologically inactive when not bound to magnesium.
In other words, our muscles need magnesium for energy production.
2. Magnesium & creatine:
Creatine’s proven ability to increase muscular performance is due to its role in helping our mitochondria make ATP:
Once an ATP molecule has been used for its energy, it becomes an ADP molecule (adenosine di phosphate). The enzyme creatine kinase then turns ADP back into ATP. However in order for creatine kinase to exert its effect on ADP, ADP must be bound to magnesium. In other words, the creatine pathway needs magnesium.
Thus if you supplement creatine and are deficient in magnesium, then much of your creatine is being wasted. This explains why creatine supplements together with magnesium supplements work better than creatine alone[40,5]. It may also shed light on why some people respond less to creatine: they may have substantially lower magnesium levels.
Because our brain and nerves also need the creatine system[41,42], creatine levels in our brain determine cognitive performance  and creatine supplementation also increases mental performance , which is critical to most sports. Creatine also protects against brain toxicity, thus people who engage intense exercise frequently without supplementing creatine and magnesium may be increasing their risk of neurodegenerative conditions like Alzheimer’s.
3. Magnesium and muscle contraction & relaxation:
When muscles contract, they shorten and thus pull on the bones they are attached to, allowing us to move and exert force. When muscles relax, they restore energy and return to neutral position to allow for the next contraction. Magnesium facilitates muscular contraction and relaxation. The 2 minute video below[v1] shows what happens during muscular contraction & relaxation and how magnesium is involved:
To sum up, muscle fibres consist of rows of long myosin filaments staggered in between rows of actin heads, running parallel to the muscle fibre they are in. The muscle fibres shorten when the myosin heads bind to the actin filaments: this causes the muscle to contract.
Calcium, ATP and ADP are all needed for the myosin to continuously bind and release actin enough times to complete a full contraction. Both ATP and ADP must be bound to magnesium in order to work.[11,20,37,47] Once the muscle is fully contracted, calcium must leave the environment and re-enter the muscle fibre’s sarcoplasmic reticulum from whence it came, in order for the muscle to relax again. Magnesium is required for the uptake of calcium into the sarcoplasmic reticulum. [11,47-51]
Magnesium also plays a key role in regulating the speed of muscular contraction by modulating actin binding and ADP release in myosin, based on its role in five different types of myosin filaments found in skeletal, smooth, and cardiac muscle.
Simply put, muscular contraction and relaxation depends heavily on magnesium, which helps explain why muscle spasms and twitches are one of the most common symptoms of magnesium deficiency.
4. Magnesium activates our muscles:
Before our muscles contract, they must first be activated by our nervous system:
The neuromuscular junctions are the points at which our nerves attach to our muscle cells. Our brain sends signals that pass through our spinal cord and then along its outwardly-extending nerves which end up at these neuromuscular junctions. When the signal passes from the nerve to the muscle fibre, it stimulates the release of calcium from the fibre’s sarcoplasmic reticulum into the space surrounding the actin and myosin filaments. Calcium’s interaction with troponin unblocks tropomyosin, allowing myosin to bind to actin and start the muscular contraction.
Reading our brain & nervous system page explains how the transmission of nervous signals, as well as the entire central nervous system as a whole, are dependent on magnesium.  Simply put, muscular contraction itself, as well as the nervous signalling that stimulates it, are both dependent on magnesium.
5. Magnesium builds & repairs muscle:
The biological process of building muscle (muscle protein synthesis) is one where our muscle cells assemble the digested amino acids from the protein we ate, into more specific proteins that add to our muscle tissue. Both phases of muscle protein synthesis are impossible without magnesium:
1. Selecting and copying the section (gene) of our DNA that has the instructions to build a muscle-protein. This phase is magnesium-dependent for several reasons:
- The DNA helicase and topoisomerase enzymes that unwind our DNA so the gene can be copied, are magnesium-dependent. [53-57]
- The RNA polymerase enzyme which makes the copy of the gene once it has been unwound, is magnesium-dependent. [58-60]
- The DNA ligases which continuously repair these genes that have the instructions to make muscle proteins, are also [61,62]magnesium dependent.
2. The process of turning this newly copied gene into an actual muscle protein. This phase is magnesium-dependent because the enzyme responsible for this process – the ribosome – also uses magnesium to function.[15,16]
Simply put, the human body requires magnesium in order to build muscle, which explains why magnesium deficiency is associated with decreased muscle protein synthesis. We know building muscle requires magnesium, but what stimulates it?
Magnesium stimulates muscle building
Muscle cells engage protein synthesis in response to three related stimuli:
- Intense exercise (requires magnesium for ATP/energy)
- Growth factors/hormones: IGF, insulin, human growth hormone (all made via magnesium-dependent protein synthesis)
- Spikes in blood amino acid levels – (whose digestion is magnesium-dependent)
Not only do these factors require magnesium, but they all stimulate muscle protein synthesis by activating a cell-signalling pathway called mTOR: mammalian target of rapamycin.[64-73] This is the major pathway for all cells including muscle cells to stimulate protein synthesis.[74-79]
It does this by reducing protein breakdown/recycling known as autophagy [80-85], while simultaneously increasing factors of protein synthesis such as the function and even creation of new ribosomes,[86-88] the enzymes that assemble amino acids into proteins. The mTOR pathway is magnesium-dependent:
While mTOR’s complexity spans beyond the scope of this article, the critical factor here is that this muscle-building pathway is regulated and facilitated by magnesium both directly, and via ATP, which explains why low ATP causes a reduction in mTOR signalling and thus protein synthesis[76,90], and why mTOR inhibitors operate by competing with ATP. [91,92] Let’s remember: ATP must be bound to magnesium as Mg-ATP, in order for this to work.
Simply put, our muscle cells’ mTOR pathway for building muscle, is magnesium-dependent.
6. Magnesium, performance & hormones:
Magnesium enhances energy
Magnesium’s role in every major factor of muscular structure and function helps explain why magnesium supplementation is shown to improve overall physical performance, while a deficiency reduces performance.[93-99]
These performance enhancing effects can be attributed to several additional factors, including magnesium’s raising of red blood cells and hemoglobin levels thereby increasing oxygen delivery to the muscles:
Magnesium is shown to increase oxygen uptake, delivery and efficiency of use in both athletes[101-104], and older women, and its deficiency results in increased oxygen requirements during exercise.
This leads to another energy related, proven mechanism of magnesium’s performance-enhancing effects: it increases glucose and thus energy in our muscles and brain. This helps explain why magnesium supplementation enhances the effects of creatine supplementation, which is largely related to glucose and energy production.
While keeping on the theme of energy for muscular performance, physical activity is known to reduce thyroid hormone: the most potent hormone for increasing human energy production. Magnesium supplementation prevents thyroid hormone from dropping during and after exercise.
Magnesium & testosterone
Increased magnesium intake is also associated with strength gains, including performance in compound resistance exercises like the bench press. This can be attributed both to magnesium’s profound impact on energy metabolism, and its strong association with anabolic hormones IGF-1 and testosterone, which explains why magnesium is shown to raise testosterone levels.
Magnesium’s effects on our testosterone levels should come as no surprise however, because it is impossible for the human body to make testosterone without magnesium: Testosterone is a steroid hormone, meaning our body makes it out of cholesterol. The conversion of cholesterol into testosterone requires the enzymes: p450ssc and p450c17. All enzymes in the p450 family are magnesium-dependent.
Simply put, any efforts to raise testosterone in our body naturally while we are magnesium deficient, cannot possibly yield maximal results.
7. Exercise, magnesium deficiency & disease:
Our nervous and muscular systems’ dependence on magnesium help to explain why intense and endurance exercise significantly deplete magnesium and increase magnesium requirements [114-116]. Thus it is no surprise that active people and athletes are usually deficient in magnesium. Under certain circumstances, such a deficiency can directly increase risk of major diseases. Think about it logically:
Protein synthesis – which requires magnesium – is needed for building and repairing muscle, AND for the daily regeneration of our DNA and vital organs. Furthermore, magnesium itself is also required for the energy production, and more specific functions of all our body’s vital systems.
When we engage in intense exercise, we activate our nervous system’s fight-or-flight response. This causes our body to prioritize our magnesium for the protein synthesis of our muscles before our organs, because our muscles are what the body uses in a fight-or-flight situation.
The problem is that this environment of muscle protein synthesis prioritization can last for up to 36 hours.[117,118] Therefore, if an athlete trains intensely 4-5 times per week, and does not supplement the lost magnesium that was used for training recovery, then their DNA and organs suffer from operating in a magnesium deficient state, which helps explains why magnesium supplementation reduces DNA damage in professional athletes.
8. Solutions to restore magnesium & improve performance & health.
The reality is that 100% of athletes and highly physically active people who do not supplement with magnesium, are in fact deficient. Based on magnesium’s essential roles in the human muscular system, supplementing with magnesium can have both performance and long-term health benefits for athletes. A complete magnesium restoration protocol can include:
- Eating a magnesium-smart diet. Learn more
- Reducing the environmental, psychological and physical stressors that deplete magnesium from your body. Learn more
- Practicing diaphragmatic breathing after workouts to disengage the body’s stress-response pathways, which deplete magnesium when active.
- Using a quality trans-dermal magnesium supplement to restore whole-body magnesium levels. Also, consider combining this with an oral magnesium-taurate, magnesium-orotate or magnesium-glycinate supplement for added mental, cardiovascular and cellular support. Learn more