Magnesium is a key mineral for humans. It plays an important role in a huge number of processes in our bodies. It has been linked to strong bones, better sleep, lower blood pressure, preventing migraines and helping against depression. But in this article we will stick to its possible benefits for athletes and—in particular—the process of muscle building and recovery.
What is it?
Magnesium is a silver-white, alkaline earth metal. Due to Western diets a lot of people do not consume enough of it each day. Roughly a quarter of the body’s magnesium is found in muscle tissue, and it is involved in 325 different processes in the human body.
What does it do for athletes?
Magnesium plays a key role in both anaerobic and aerobic energy production. That’s why we cyclists are interested in it. One study found that athletes—gymnasts, footballers and basketball players—only consumed 70% of their daily requirement, while female runners only eat 59% of their minimum daily requirement.
The metal is key for the body’s energy production: ATP, which transports chemical energy for metabolism, cannot work without it. It is also key for the structural integrity of body proteins, and helps deliver calcium to nerve cells. Magnesium has a very important role in muscle efficiency, including energy production and oxygen uptake. But pain cavers take note: magnesium is lost in sweat, which is why it is an ingredient in many of those expensive, electrolyte-rich recovery drinks.
Unfortunately, many of the studies involving athletes and magnesium are not very consistent. But there is some evidence that too-little magnesium in athletes means they use more oxygen than those with optimal levels, and low levels are linked to cramp, excessive fatigue, mood swings and restless muscles.
No, the stuff you rub on your hands is not the stuff you eat. Weightlifters and climbers use magnesium carbonate (MgCO3) to help their grip. Photograph: Getty Images.
Should I take it in pills?
So it’s clear: us cyclists should make sure we at least get enough magnesium if we are to get the best out of ourselves. So, should we grab the pills from the store and start munching? Well, be careful, is what we say—there are side-effects.
Magnesium oxide is an ionic compound, and magnesium citrate is a salt of magnesium. Both of these forms of magnesium are available in your local store as dietary supplements. But what do they mean? Magnesium oxide (chemical formula MgO) is a relatively simple compound, whereas magnesium citrate (chemical formula C6H6MgO7) is a magnesium salt of citric acid. Long story short: magnesium oxide has high levels of magnesium. It is cheap. But it absorbs much less well into your body than magnesium salt, such as (the more expensive) magnesium citrate.
Magnesium: to take, or not to take? That is the question. Photograph: Getty Images.
If you do decide to take magnesium in pill form be aware that it can upset your stomach and have a laxative effect. Also, if you take it too regularly, you may develop laxative dependence. This basically means your bowels get used to it and work less well without it. Also, talk to your doctor if taking antibiotics, as magnesium can reduce their effect.
The daily recommended amount of magnesium is up to 400mg a day. Some say you need to consider taking 600mg of magnesium oxide in order to get the required dosage, as it does not absorb well into the body.
What foods are rich in magnesium?
Magnesium is essential for overall health and especially for those of us who take our training, recovery and diet seriously. But the best way to get it is the natural way, of course. The richest natural sources of magnesium are pumpkin seeds, brazil nuts and almonds. But spinach, broccoli, avocados, bananas, black-eyed peas, brown rice and quinoa are also rich in this muscle-friendly mineral.
Or just take a bath in it!
Weirdly, magnesium is also absorbed into your body through your skin. So after a long, tough ride you can simply soak in the bath in magnesium sulphate. Sounds strange? The famous brand name Epsom Bath Salts is actually magnesium sulphate, but don’t soak in it for more than 30 minutes… Now you know!