Magnesium For Runners: Benefits, Food Sources And Supplements

Magnesium doesn't receive as much attention from runners as carbohydrates, protein or electrolytes such as sodium, but it is an essential mineral with an important role in normal muscle function, energy production and bone health.

That makes magnesium important for runners, although its benefits are sometimes exaggerated. Taking extra magnesium won't automatically improve your running performance or stop you getting muscle cramps. For most runners, the priority should simply be making sure you're getting enough through a varied diet.

So how much magnesium do runners actually need, which foods provide it and is there ever a reason to take a magnesium supplement?

What Is Magnesium?

Magnesium is an essential mineral involved in hundreds of processes within the body. It contributes to normal muscle and nerve function, helps the body release energy from food and plays an important role in maintaining healthy bones.

The body cannot produce magnesium, so it needs to come from your diet. Fortunately, magnesium occurs naturally in a wide range of foods, including nuts, seeds, whole grains, pulses and green leafy vegetables.

For runners, its involvement in muscle function and energy metabolism makes magnesium particularly relevant, but that doesn't mean consuming more than you need will necessarily make you run faster or recover more quickly.

Why Is Magnesium Important For Runners?

Every time you run, your muscles repeatedly contract and relax while your body produces large amounts of energy to keep you moving. Magnesium is involved in processes that support both normal muscle function and energy metabolism.

It also contributes to bone health, which is particularly relevant in a sport involving repeated impact. Runners therefore need an adequate magnesium intake in the same way that they need sufficient calcium, iron and other essential nutrients.

Small amounts of magnesium can also be lost through sweat during exercise. However, this doesn't mean every runner needs additional magnesium or that runners should automatically take supplements. A varied diet will provide enough for most people.

Magnesium And Energy Production

One of magnesium's most important roles is its involvement in energy metabolism. The body uses energy stored in adenosine triphosphate, better known as ATP, and magnesium is required for many of the reactions involved in producing and using that energy.

This is clearly relevant to running, where energy demand increases substantially during exercise. However, there's an important distinction between needing magnesium for normal energy metabolism and taking additional magnesium to increase your energy.

If you're already consuming enough magnesium, taking more isn't likely to provide an additional energy boost. The goal is therefore to avoid inadequate intake rather than treating magnesium as a performance-enhancing supplement.

Can Magnesium Prevent Muscle Cramps When Running?

Magnesium is probably best known among runners as a supposed cure for muscle cramps. You'll find numerous supplements marketed on this basis, but the scientific evidence is much less convincing than the advertising can suggest.

Exercise-associated muscle cramps are complex and are increasingly thought to involve neuromuscular fatigue rather than being caused simply by losing a particular mineral through sweat. Hydration and electrolyte balance can still be relevant, particularly in demanding conditions, but cramps can't usually be blamed on magnesium deficiency alone.

There is currently insufficient evidence to say that taking magnesium supplements prevents exercise-associated muscle cramps. If you are deficient in magnesium, correcting that deficiency is important for normal muscle function, but taking additional magnesium when your intake is already adequate shouldn't be considered a reliable way of preventing cramps.

Training appropriately for the demands of your event, pacing sensibly and developing a hydration and fuelling strategy are likely to be more useful considerations for runners who experience cramps during races.

Does Magnesium Help Running Recovery?

Magnesium contributes to normal physiological processes that are involved in muscle function and energy metabolism, so consuming enough is part of supporting normal recovery from training.

However, claims that magnesium supplements significantly accelerate recovery, eliminate muscle soreness or allow runners to recover more quickly should be treated cautiously. Research doesn't currently support recommending magnesium supplementation as a general recovery strategy for runners who already consume enough.

Good recovery still depends primarily on appropriate training, sufficient food and carbohydrate, adequate protein, hydration and good-quality sleep. Magnesium is part of that overall nutritional picture rather than a shortcut to faster recovery.

How Much Magnesium Do Runners Need?

In the UK, the recommended daily amount of magnesium for adults aged 19 to 64 is 300mg for men and 270mg for women.

You will sometimes see higher magnesium recommendations specifically for athletes because exercise can increase losses through sweat and urine. However, there isn't a separate official UK magnesium recommendation for runners or endurance athletes.

Rather than automatically increasing your intake or taking a supplement because you run regularly, the more useful approach is to eat a varied diet containing magnesium-rich foods.

Runners with particularly restrictive diets or concerns about their nutritional intake may benefit from discussing this with a registered dietitian, sports nutritionist or healthcare professional.

What Are The Signs Of Magnesium Deficiency?

True symptomatic magnesium deficiency caused simply by inadequate dietary intake is uncommon in otherwise healthy people because the kidneys help the body conserve magnesium when intake is low.

When deficiency does occur, early symptoms can include loss of appetite, fatigue, weakness, nausea and vomiting. More severe deficiency can cause numbness, tingling, muscle contractions or cramps and abnormal heart rhythms.

Muscle cramps or tiredness on their own aren't evidence that you have a magnesium deficiency. Both are extremely common among runners and can have numerous causes, including training load, insufficient recovery, inadequate fuelling and other nutritional issues.

Certain medical conditions and medications can increase the risk of magnesium deficiency, so anyone concerned about persistent symptoms should speak to a healthcare professional rather than simply starting a high-dose supplement.

Read more about running nutrition mistakes here.

The Best Magnesium Rich Foods For Runners

Most runners can obtain plenty of magnesium through normal food. Good sources include spinach and other green leafy vegetables, nuts, seeds, beans, lentils and whole grains.

Pumpkin seeds, almonds and cashews are particularly useful sources and can easily be added to porridge, yoghurt or salads. Wholemeal bread and other wholegrain foods can also make a useful contribution to daily intake.

Dark chocolate contains magnesium too, although obviously it doesn't need to become your primary magnesium strategy. Building meals around a varied selection of whole foods is a much more effective way of obtaining magnesium alongside the many other nutrients runners need.

Should Runners Take Magnesium Supplements?

Most runners don't need a magnesium supplement if they're eating a varied and balanced diet. Supplements may be appropriate in some circumstances, but taking one simply because you're a runner isn't necessary.

If your diet is particularly restrictive, you struggle to consume magnesium-rich foods or a healthcare professional has identified a reason why your magnesium status may be low, supplementation may be worth discussing with them.

It's also important to remember that more isn't better. High supplemental doses of magnesium can cause diarrhoea and other gastrointestinal problems, which certainly isn't something you want immediately before a long run or race.

Different forms of magnesium are widely available, but runners shouldn't get too distracted by marketing claims around particular formulations unless there is a specific reason for supplementation. Your overall intake and whether you actually need additional magnesium are more important questions.

Read more about supplements here.

Magnesium And Bone Health

Magnesium isn't only important for muscles. A significant proportion of the body's magnesium is stored in bone, and the mineral contributes to maintaining normal bone health.

This matters to runners because bones are repeatedly exposed to impact during training. Magnesium should therefore be considered alongside other important factors such as calcium, vitamin D, adequate energy intake and resistance exercise when thinking about long-term bone health.

Again, the important point is adequate nutrition rather than simply taking more magnesium. Bone health depends on numerous nutrients and lifestyle factors, and no single mineral can compensate for an otherwise inadequate diet.

Is Magnesium Important For Runners?

Magnesium is essential for normal muscle function, energy metabolism and bone health, making it an important part of a runner's diet. What the evidence doesn't show is that every runner needs additional magnesium or that taking supplements will automatically improve performance, speed up recovery or prevent muscle cramps.

For most runners, the best approach is straightforward. Eat a varied diet containing plenty of whole grains, nuts, seeds, pulses and green vegetables and you'll probably obtain the magnesium your body needs alongside many other important nutrients.

If you have a restrictive diet, persistent symptoms or concerns about deficiency, seek professional advice rather than assuming a magnesium supplement is the answer. Magnesium matters to runners, but getting enough is far more important than getting extra.