How to recognize and treat a deficiency
As a health care professional, you’re likely well aware of how crucial magnesium is for normal cell function, as well as several metabolic processes. Canada’s Natural Health Products Directorate (NHPD) recommends a daily allowance of 20 to 500mg of magnesium per day for adults – this is the minimum amount required to avoid a deficiency. It is estimated that more than half of the population may, in fact, be deficient in magnesium, with some dietary surveys putting that rate up higher still to 70%.
However, athletes are not your average patients with typical magnesium requirements. For hard training or endurance athletes, the suggested daily amounts are between 400 and 800mg daily. There is emerging evidence that athletes have higher magnesium needs than people who may not exercise as much or as hard. Those who constantly push their bodies to the limit can ironically be lacking in one of the most important minerals they need to take their athleticism to the next level.
How athletes benefit Magnesium is used by athletes in these important ways:
- For energy production, first and foremost – athletes typically expend more energy and therefore require more magnesium.
- To be absorbed and utilized at a high rate by the nervous system during strenuous exercise.
- For assisting in the removal of accumulated lactic acid and fueling DNA repair enzymes, post-exercise.
- To replace what’s lost through sweat after intense exercise.
Even symptoms that many athletes typically accept as the hazards of hard training may actually be the result of a deficiency, which can be alleviated by magnesium supplementation. As athletes tend to be most focused on their physical performance, activities like energy production and muscle strengthening tend to become more primary functions, leaving less magnesium available for secondary functions, like their immune system.
How much magnesium is in the human body?
20 to 28g (equivalent to almost one ounce or the volume and weight of one tablespoon of flax seeds or sesame seeds)
- 59% is in the bones
- 40% is in muscles and tissues
- 1% is in extracellular fluid
All of the additional demands athletes put on their bodies also makes them more susceptible to suppressed immune function, which can open the door to infection, most commonly of the upper respiratory tract. The study “Exercise, Magnesium, and Immune Function” (Laires, 2008) found a magnesium deficiency not only impairs the ability of the body to do physical work, but can also impair optimal immune function. Magnesium, the study suggests, has a strong bond within the immune system to both non-specific and specific immune function, and a magnesium deficiency can lead to “immunopathological changes” that trigger the body’s inflammatory response.
Greater staying power
Endurance athletes are especially prone to magnesium deficiency, as their stores can be quickly depleted when they work up a sweat or increase their energy output. Interestingly, taking magnesium supplements has actually shown improvement in cellular metabolism in competitive athletes (Golf et al, 1998). Saris et al (2000) reported that adults who participated in moderate physical training while supplementing with magnesium actually showed improved cardiorespiratory function during a 30-minute submaximal exercise test. Siebrecht (2013), in his review of the safe supplementation of magnesium in human nutrition, echoes that research like this suggests a potentially beneficial effect of magnesium supplementation on muscle metabolism.
A study by Cinar et al (2007), concluded that exercise performance improved with magnesium supplementation in subjects that exercised 90 to 120 minutes, five days per week. It’s thought that magnesium works to increase red blood cell count and hemoglobin levels, allowing for greater oxygen distribution in the body. Magnesium plays an important role in increasing oxidative capacity, which in turn can enhance endurance training for your athletetic patients.
Recharge the ATP battery
ATP, the compound that when broken down releases energy for cellular function, needs magnesium to work. Magnesium is crucial for energy metabolism because it activates enzymes known as ATPases, which are needed to generate ATP. When ATP is broken down, energy is released for all of the body’s muscle contractions. During strenuous exercise, this turnover is extremely rapid, meaning that ATP needs to be synthesized quickly – especially since the body cannot easily store ATP (and frequently what gets stored is used up within seconds). The body does this in two ways: through aerobic metabolism (with oxygen), used during endurance activities like marathon running, and anaerobic metabolism (without oxygen), used during weight training.
Strengthening muscle with magnesium
There is data suggesting magnesium levels in the body are indirectly related to strength improvement. A study published in the Journal of the American College of Nutrition measured the effects of a dietary magnesium supplement on strength development during a double-blind, seven week strength training program in 26 untrained subjects. Results showed that the oral magnesium supplementation group produced significantly increased strength outcomes than the control group. It has also been noted in research studies that maximal contraction of the quads is positively correlated to serum magnesium status (Stendig-Lindberg et al, 1983).
Why do we get muscle cramps?
The reason muscle cramps occur is not that well understood. Exercise-induced muscle cramps may be related to neuromuscular fatigue and shortened muscle contraction (continued shortening through prolonged use prevents muscle from relaxing). They are also thought to be caused by dehydration and electrolyte loss – in particular, sodium and magnesium loss, in hot and humid conditions. This may be due to the fact that mineral losses through sweat are increased during long exercise periods.
Magnesium is also used in the RNA process to create proteins. This type of protein synthesis depends on high magnesium concentrations, and it’s thought that low magnesium levels may adversely affect protein manufacture and metabolism. For the athlete, this results in lowered strength gains during workouts – not the payoff they’re looking for. This means athletes on high protein diets should also be advised to up their magnesium intake as well, in order to maintain adequate magnesium levels needed for protein synthesis.
Prescribing magnesium to your active patients
You might think about prescribing magnesium to your more active patients or clients, if you’re not already. Helping them understand the underlying mechanics behind supplementation can help with compliance, perhaps more so than with other patients, as athletes already have a vested interest in their health and performance.
Remember, the most bioavailable form, magnesium bisglycinate, is best at a dosage of 400 to 800mg per day. Taking divided doses of 100 to 200mg at a time is recommended for maximizing absorption. Whether they prefer to take it in capsule, powder or effervescent drink form, the key to getting athletes in the habit of taking magnesium is to make it a convenient part of their workout regime.
Is it a magnesium deficiency?
Here is a quick checklist to go over with your patients:
- Ask about symptoms:
- Muscle weakness
- Muscle spasms and / or tremors
- Assess nutritional status:
- Poor health
- Screen for health conditions:
- Gastrointestinal absorption problems
- Anorexia nervosa
- Recent acute illness
- Environmental conditions:
- Very cold weather
- Medications / supplements:
- Medications that interact with
- magnesium absorption
- Supplements that interact with
- magnesium absorption
The more items checked off on this list, the more likely there is a deficiency in magnesium.
Why magnesium bisglycinate
Magnesium bisglycinate appears to be the safest and most effective form of magnesium for human absorption according to a magnesium research review published in the European Journal of Orthomolecular Medicine (Siebrecht, 2013). Magnesium bisglycinate is very stable, highly bioavailable and absorbed through a dipeptide channel in the intestine, so it doesn’t compete with other minerals like calcium. It also doesn’t bind or get excreted with dietary phosphates, phytates, oxalates, tannins or fibrous roughage.