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We need magnesium because it plays a role in over 300 enzyme reactions in your body. These reactions can help to keep fatigue at bay, maintain bone and muscle function, and also help your body maintain a normal balance of electrolytes — three essential prerequisites to perfecting strength training.
So, for women looking to increase their strength, it is essential to ensure that magnesium levels are adequate, as even a small shortfall in your magnesium intake could affect your performance. How then, do we make the most of such an important mineral?
A study published in the Journal of the American College of Nutrition1 showed substantially higher muscle gains during a seven-week weight training programme amongst participants who had taken a magnesium supplement, compared with those who had taken a placebo.
It is thought this might be to do with magnesium's role in supporting protein synthesis. Essentially, when you eat food containing protein, your digestive system breaks it down into individual amino acids. Your cells then recombine these amino acids and then link them together to form new proteins within your body - supporting muscle repair and growth. This can depend on optimal magnesium levels, so if you're thinking of increasing your protein intake, you should also consider increasing your magnesium levels to adequately support your body's protein metabolism.
In one study2 on triathletes participating in intense physical exercise, those taking a magnesium supplement had a marked increase in muscle oxygenation; a reaction magnesium is known to cause. When you lift weights, for instance, your muscles use up oxygen with every rep. Before long, your body starts to work anaerobically - producing lactic acid and leading to fatigue. Increased muscle oxygenation therefore means that the onset of anaerobic respiration can be delayed, and subsequently the onset of fatigue.
Magnesium also plays an important role in the metabolism of ATP (adenosine triphosphate), a compound found in every cell of your body. When ATP is broken down, it releases the energy needed to perform any kind of strenuous exercise - such as strength training. When you lift weights, your muscles contract, resulting in huge amounts of ATP being broken down.3 The enzymes required to break down ATP are thought to be stimulated by magnesium, so without it your body simply won't release the adequate energy it needs to perform the exercise safely and effectively.
Sleep is seen as one of the essential factors of muscle recovery - and therefore in strength training. The reason why is that poor sleep, or lack of, is a factor that can actually decrease the efficiency of your protein synthesis pathways, while increasing their degradation at the same time. Put simply, poor sleep equates to a higher chance of muscle loss, and a hindrance in muscle recovery; increasing the risk of injury.
Magnesium, however, plays a vital role in helping you sleep.4 Not only does it help your muscles relax, it can help your brain to 'switch off' through calming the body's nerves. Magnesium is also thought to play a key part in regulating your body clock. For instance, a 2015 study published in Nature5 showed it can help control how the body's cells adapt to the rhythm of night and day. Magnesium supplementation, therefore, is worth considering if you're trying to improve your strength but struggling to get in a good night's sleep.
Magnesium is involved in keeping your heartbeat regular, in maintaining your blood pressure, and preventing hypertension. So when you're putting your body under strain with strength training, having a healthy heart is more important than ever.
Magnesium helps your muscles to relax and contract, and without enough magnesium your muscles can go into spasms. It also prevents your cells from absorbing too much calcium, which can lead to muscle pains and cramps.
Despite its importance, many women are deficient in magnesium. According to the National Diet & Nutrition Survey published by Public Health England in 2014, the magnesium intake of a substantial proportion of adult women was below the recommended levels.
Eating highly-processed foods may be partly to blame, as some types of food processing, such as refining grains, substantially lower the magnesium content of foods. Yet, even if you have enough magnesium in your diet, your digestive tract may not always fully absorb it. This is especially the case if you have a bacterial gut imbalance or digestive problems.
Your absorption of magnesium may also be reduced if you drink a lot of caffeinated drinks, and if you're prone to heavy periods, your magnesium levels could be further affected.
Blood testing can reveal a magnesium deficiency, but as less than 1% of your body's magnesium is found in blood serum, a blood test may not be a reliable indicator of deficiency.
Magnesium supplements are regarded as very safe. The standard dose which is 200-400mg, and supplements should be taken daily, with food. If you like to have a shot of espresso before you hit the gym, or take a pre-workout caffeine supplement, go easy on it at other times of the day so as not to affect your magnesium absorption.
The important thing to remember, however, is to maintain a healthy diet, as magnesium is found in many foods, and is especially rich in your leafy greens and seeds. Magnesium isn't the only mineral that can help you to improve your strength though, just head over to our Elite hub to find out more.
Patricia Carswell is a health and fitness writer. She has written for all of the major newspapers and a wide variety of fitness publications, and is writer of the award-winning blog, Girl On The River.
See more of Patricia Carswell's work at Girl on the River.
Nothing beats a healthy, balanced diet to provide all the nutrients we need. But when this isn't possible, supplements can help. This article isn't intended to replace medical advice. Please consult your healthcare professional before trying supplements or herbal medicines.
1Brilla L et al. (1992). Effect of magnesium supplementation on strength training in humans, Journal of the American College of Nutrition
2Golf S at al. (1998). On the significance of magnesium in extreme physical stress, Cardiovascular Drugs and Therapy
3Jahnen-Dechent W et al. (2012). Magnesium basics, Clinical Kidney Journal
4Keefer A. Does Magnesium Aid Sleeping? , Livestrong.com
5Feeney K, (2016). Daily magnesium fluxes regulate cellular timekeeping and energy balance, Nature
6Kent L (2011). Hashimoto's and Magnesium Deficiency, Healthfully.com