Magnesium is one of those minerals that’s spoken about in athletic circles in relation to muscle relaxation, recovery and good sleep.

While these benefits hold true likely a result of magnesium’s action on the nervous system – there is still confusion around what else magnesium does, how much you might need and most importantly, are getting enough?

Let’s look at some specifics when it comes to magnesium…

Why do I need magnesium?
Magnesium plays many vital roles across health as well as performance functions, its needed for numerous things including:

  • Muscle contraction and relaxation
  • Energy production
  • Nerve function
  • Cardiac activity
  • Blood pressure regulation
  • Hormonal interactions
  • Immunity
  • Bone health 
  • Synthesis of proteins, fats and nucleic acids


Where is magnesium found?
Magnesium is not produced by the body, so it needs to be ingested daily. It’s found pretty widely in common foods, the best sources include:

  • Spinach
  • Cocoa
  • Black beans
  • Avocado
  • Pumpkin seeds
  • Almonds
  • Whole grains


So, isn’t food enough then?
Surely with a well-rounded diet, magnesium requirements could be met? Not so fast. 

There are a few reasons why you might want to keep a careful eye on magnesium intake, especially if you are an athlete.

  • Diet reality check: most of the athletes I see that claim they eat well, are still not eating enough of these magnesium rich foods on a consistent basis. So deficiencies are more common than you’d think. This is reflected in nutrition data worldwide, indicating higher levels of deficiency than expected. 
  • Training reality check: Even when we add more of these foods, training output can still make meeting requirements challenging. That’s because magnesium stores are depleted through sweat, but also used in energy production. Hard working athletes, especially in endurance sports, are continually shedding electrolytes including magnesium – even more so in hotter climates. Hours a day of hard training can add up to significant losses relatively fast, and magnesium is needed to activate ATP enzymes, which in turn generate ATP (adenosine triphosphate). When ATP is broken down, energy is released for muscle contraction meaning that when intensity or training volume is high, more ATP is needed quickly. A deficiency in magnesium just slows or limits this process, with the obvious result being fatigue, a drop in power, or even cramps scenarios an athlete wants to avoid. In the case of long-term deficiencies, magnesium is predominantly stored in bone and sufficient quantities are critical for bone health; continually not getting enough magnesium may have implications for bone mineral density down the track.
  • Food quality: The magnesium content of foods reflects soil content. While some soils are rich in magnesium, many others aren’t – so those ‘rich’ sources of magnesium (like leafy greens), may not actually be contributing much at all. 
  • A changing understanding: Research suggests magnesium requirements for performance as well as health may be far higher than we used to think was adequate. As we understand more about the human body and how it best functions, some guidelines are becoming outdated, including recommended levels of micronutrients such as magnesium and vitamin D. 


All of this indicates to me that magnesium deficiency or risk of deficiency is high amongst athletes, and that even carefully planned diets may not meet all requirements all of the time. 

A quality supplement in a form that is well absorbed is worth considering. And if you’re wondering about the best time to include a supplement? My recommendation is 30 minutes before bed. That will work with your nervous system to facilitate recovery and relaxation of muscles and optimise sleep.