You had an exhausting day at work barrelling through emails and meetings. Then you dragged yourself to the gym and you tried hard. You tested yourself with some limit bouldering. Then max hangs, weighted pull-ups, bench press, and even core. When you finally leave for home, you’re completely and utterly exhausted. At least I’ll sleep well tonight, you think.

Wrong. Because even though you eat, shower, and then lay down by 11 p.m., the hours tick by. Suddenly your alarm goes off and you only slept an hour or two, the rest of night spent desperately tossing and turning and counting sheep. 

Sound familiar? I’m guessing most climbers can relate. Climbing hard is hard, and it can give you this electric buzz that just won’t let you drift off. On more than one occasion, I’ve desperately Googled, “Why can’t I sleep after working out?” only to find shitty answers like, “Drink more water,” and “Try cooling down.” Thanks, Google.

Last winter, I started going to a fancy recovery-focused gym in Denver. They have contrast baths, compression sleeves, saunas, and a bunch of other shit that makes you feel like a real athlete. One day I was sitting in the sauna across from a firefighter, and he was telling tales from the field, which were all horrific and gory and incredibly interesting. Naturally, given our setting, he got to talking about recovery and how to do it faster. Magnesium he says. No, he doesn’t just mention it—he won’t shut up about it. It helps get you right to sleep, he says, so take it before bed. Hmmm… My interest piqued and I bought some that night. 

ALSO READ: The Best 14 Tips To Sleep Well While Camping

I’m not a doctor, and you should talk to one if you want medical advice. But I can easily see why the dude went on and on about magnesium. It works. No, seriously, it works. I even canceled the expensive membership at the recovery gym, because it turns out sleep is better than contrast baths. 

I did some research, and it turns out 45 percent of Americans are deficient in magnesium, and that’s just deficient in terms of recommended daily dosage, not the optimal-for-climber-performance dosage. And magnesium does so much more than help you sleep. It is critical for energy production as well as protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Demand for magnesium increases with activity and stress. Climbers, therefore, will likely need more magnesium than those who do no exercise. Because it is an essential mineral, your body cannot synthesize it—it must be consumed.

So, do you need more magnesium in your diet? What does the science say, exactly, as to what it does and how it might benefit athletic performance? Does it really help with sleep? Let’s discuss.

Athletic Performance and Sleep

Ms. Frizzle, the magic school teacher, told us the mitochondria is considered the “powerhouse of the cell.” It’s where ATP is produced, which is the molecule that stores and transfers energy in cells. In addition to being critical for increasing the total number of mitochondria within tissues, magnesium also binds to ATP to form the Mg-ATP complex. This complex is indispensable for nerve function, muscle contraction, and blood pressure regulation. Many scientific studies back this up in different ways, demonstrating that magnesium supplementation can increase holistic athletic performance.

Animal models demonstrating the benefits of magnesium on strenuous activity are well-established. Rodents reliably show improvements in compulsory physical tasks, such as swimming, when supplemented with magnesium. Human physical performance after magnesium supplementation has been documented benefiting all types of people, from students with increased muscle function to postmenopausal women with extra energy. Even patients with chronic diseases, such as heart disease, show decreased inflammatory markers with magnesium supplementation.

Notes on Trying Hard (Like Really Hard) in Climbing

And what about sleep? Somewhat surprisingly to my own conclusion, the studies aren’t totally decisive. “The data are mixed on this,” says sports dietitian Marisa Michael, MSc, RDN, CSSD. “Magnesium supplementation may help with sleep quality and duration, especially in people who are deficient, however it is not conclusive to say that magnesium will definitely help with sleep.”

Still, some studies do indicate that magnesium helps to activate the parasympathetic nervous system, which calms the body down. This is in line with my personal experience of taking the supplement. That buzzy feeling after training? It goes away after taking magnesium. My boyfriend said the same thing, and so did that firefighter. And other studies suggest that magnesium may help improve sleep quality by positively affecting hormones that regulate sleep, such as renin and melatonin.

To Supplement or Not?

The Recommended Dietary Allowance (RDA) for magnesium is 400 to 420 milligrams and 310 to 320 milligrams for males and females, respectively, above the age of 19. But RDA simply refers to the recommended dosage to meet nutritional requirements, and it is not meant to define what an athlete should take for optimal performance. Demand for magnesium increases with metabolic stress, so everything from pregnancy to exercise will mean an increased need for magnesium. 

To be clear, however, there really isn’t evidence to support the idea that more magnesium will help your exercise performance or improve your sleep if you’re already getting enough. That is to say, excess is not necessarily helpful. But the evidence does indicate that most people simply don’t get enough.

How do you know if you’re not getting enough? A large US national survey demonstrated the average magnesium intake is approximately 320 milligrams per day for men and 230 milligrams per day for women, which both fall short of the RDA, let alone what your requirements may be with added stress and training. The symptoms associated with low magnesium are broad and unspecific; such as low energy and muscle cramping. To make things worse, while there are methods of testing your magnesium levels, for complicated reasons they aren’t considered particularly reflective of your true status. (Blood measurements, for example, can sometimes mask a deficiency rather than reveal one.)

Luckily, the risk of consuming too much magnesium is extremely low. Especially if you focus on consuming more magnesium-rich food, rather than taking a supplement. Magnesium is found in chlorophyll, so it will be present in green leafy vegetables. Spinach and kale are both excellent sources. So are almonds, pumpkin seeds, and even bananas. You can find charts with a quick Google search.

Some things to keep in mind: grains such as brown rice and oat bran and legumes are, despite their high magnesium content, poor choices for obtaining magnesium because the bioavailability is incredibly low. Also, because magnesium is soluble, boiling veggies can result in a serious loss of the mineral. 

Drink alcohol? Or eat lots of sugar and/or fatty foods? Those things, by the way, have been shown to impair magnesium absorption or increase magnesium excretion.

I already eat tons of magnesium-rich food (yes, I’m the person that eats a big salad a day). I personally found supplementing to still be noticeably helpful. There’s tons of different types of supplements out there. I take magnesium citrate, which is a highly bioavailable form and has the added benefit of keeping things moving in the gut, if you know what I mean. (That said, I highly caution not using more than the recommended serving size so things don’t move too much!). There are other good ones out there, too, like magnesium glycinate, magnesium malate, magnesium orotate, and more. This video briefly discusses the differences. The one to stay away from is magnesium oxide, as it has a low bioavailability. 

Supplementing magnesium helped my sleep, and I’m convinced it has helped me to recover faster. Maybe that’s purely a factor of the sleep. Or it’s all a placebo. In any case, it has helped my climbing. 

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