Why do athletes take magnesium? When a runner asks me that, my first thought is that it is really two questions. Are you low, and does extra help if you are not?
The short answer: Athletes use magnesium because muscles, nerves and energy all need it to work normally. Hard training loses more of it in sweat and urine, which may raise needs by 10% to 20%. Getting enough supports normal performance, and extra does not make you faster if you already get enough. Many athletes also keep a magnesium balm in the gym bag for a massage after a run.
By Dr. Doug Strobel, MD, a board-certified neurologist who formulated Dr. Doug's balms. Last reviewed October 13, 2026.
Six reasons, graded by the evidence
In clinic, runners hand me the bottle and ask if it is doing anything. I'm a board-certified neurologist who was a Marine and a Navy pilot before medical school, and I still run obstacle races, so I have asked my own gym bag the same question. Here are the six reasons athletes give most, graded by what the research shows.
1. Athletes lose more magnesium than other people
Grade: well supported. Hard exercise makes you lose more magnesium in urine and sweat. That may raise your needs by 10% to 20% (Nielsen and Lukaski, Magnesium Research, 2006).
The same review gives a warning line. Male athletes eating less than about 260 mg a day, and female athletes eating less than about 220 mg, may run low. Athletes in weight-control sports, like wrestling and gymnastics, are most at risk.
2. Magnesium is needed for normal muscle function and energy
Grade: well supported (basic body science). Magnesium is part of more than 300 chemical reactions in the body. These include making and storing energy, normal muscle and nerve function, and blood sugar control (Volpe, Current Sports Medicine Reports, 2015).
In a muscle, calcium helps a fiber tighten. Magnesium is part of how it relaxes.
3. Athletes hope it will improve performance
Grade: only if you're low. Magnesium pills help exercise performance in people who are short on magnesium. But giving extra to people who already get enough has not been shown to help (Nielsen and Lukaski, 2006).
So the first move is food: leafy greens, nuts, seeds, beans and whole grains. If your doctor thinks you're short, a pill may make sense. For help choosing a form, see magnesium glycinate vs citrate vs chloride.
4. Athletes use it hoping to stop cramps
Grade: not supported for exercise cramps (not yet studied). A Cochrane review looked at 11 trials. It found no real trials at all of magnesium for muscle cramps during exercise. It also found magnesium by mouth is unlikely to do much to prevent night cramps in older adults (Garrison, Cochrane Database of Systematic Reviews, 2020).
As a neurologist, I find the cause of these cramps more interesting than the supplement. A 2009 review in the British Journal of Sports Medicine looked at the old idea that exercise cramps come from salt loss or dehydration. That idea rests mostly on stories and small case reports. Four studies that followed athletes over time did not support it. The evidence now points more to the nerves losing control of tired muscles (Schwellnus, British Journal of Sports Medicine, 2009). That fits with why stretching the cramping muscle is still the fastest fix in the moment. I go deeper in magnesium cream for leg cramps.
5. A magnesium balm makes post-workout massage easy
Grade: practical, and the topical research is small. A balm lets your hands glide for a calf or quad massage. It moisturizes the skin, and it works right where you put it.
A lab study on human skin found magnesium crossed the outer layer. More got in with stronger products and more time. Hair follicles, the tiny openings hairs grow from, did a big share of the work (Chandrasekaran, Magnesium Research, 2016). Human studies are small. What a balm does reliably is turn recovery into a two-minute habit you will actually keep.
6. A balm protects skin from friction on long efforts
Grade: practical (a cosmetic barrier). Any balm with beeswax and oils forms a thin, slick layer. That cuts down rubbing on heels, toes, thighs and under straps.
The base does this job, so it applies to any well-made balm. Blisters and chafing come up again and again in our reviews from runners and hikers. Many people put a thin layer on hot spots before a long run or hike. Reapply on long days.
The six reasons, side by side
| Reason | What athletes hope | What the evidence says |
|---|---|---|
| Higher losses | Replace what sweat and urine take | Supported: needs may rise 10% to 20% |
| Muscle and energy function | Normal muscle and nerve function | Supported: basic physiology |
| Performance | Go faster or longer | Only helps if you're low |
| Cramps | Prevent cramps | Not studied for exercise cramps; oral didn't help older adults' night cramps |
| Massage with a balm | Easier, consistent self-massage | Practical; topical research is small |
| Friction protection | Fewer hot spots | Practical cosmetic barrier |
What I put in my balm
Our Magnesium Balm is magnesium chloride in olive oil, coconut oil, beeswax and shea butter, with peppermint and lavender essential oils and vitamin E. I made a magnesium balm for my clinic patients and for myself first. I wanted to formulate a product unlike others on the market. I chose magnesium chloride because, for topical magnesium, it's the best there is. My goal: the most magnesium chloride possible that still absorbs in completely, with no sting, no grit and no pins-and-needles tingle, in a handful of clean, non-toxic ingredients. Only goodness and nourishment that truly helps. The magic happens when you massage it in completely. The 2.5 oz twist-up stick fits a gym bag or race belt, and there's a 0.5 oz mini for a pocket.
How athletes use a magnesium balm: pick, rub, repeat
- Pick your spot. Calves, the Achilles area, arches, quads, hamstrings, hips, lower back or shoulders. For hot spots, a thin layer on heels, toes or thighs before long efforts. Start small. Most people use too much.
- Rub it in. Use my 5-inch rule: cover the spot plus about 5 inches above, below and all the way around it. Massage until it disappears.
- Repeat. Any time works: before a run, after a run, at the trailhead or at night. Skip broken or irritated skin.
Picture the finish chute: no hot spots on your heels, a stick in your race belt, and two minutes on your calves before you head home.
Related reading
- Magnesium Balm Benefits for Sore Muscles: A Neurologist's Recovery Guide
- Magnesium Cream for Leg Cramps: Does Topical Work Better Than Oral?
- Does Topical Magnesium Absorb Through the Skin? A Neurologist Reads the Research
Frequently asked questions
Why do athletes take magnesium?
Athletes take magnesium because their bodies need it for normal muscle and nerve function and energy. Hard training raises losses in sweat and urine, which may increase needs by 10% to 20%. Getting enough supports normal performance.
Do athletes need more magnesium?
Athletes probably need somewhat more magnesium than people who don't exercise. A review estimated hard exercise may raise needs by 10% to 20%, and athletes in weight-control sports are most likely to fall short.
Does magnesium improve athletic performance?
Magnesium improves athletic performance only in people who are low. Giving extra magnesium to athletes who already get enough has not been shown to help.
Which magnesium do athletes use?
Athletes who need a magnesium supplement often choose glycinate or citrate, which tend to be easier on the stomach than oxide. Topical magnesium chloride in a balm is used for massage, not to raise whole-body levels.
Why do runners take magnesium?
Runners take magnesium for the same reasons as other athletes. Long, sweaty training raises magnesium losses, and muscles need magnesium to work normally. Food comes first, and a supplement only helps if you are low.
Does magnesium prevent cramps during exercise?
Magnesium has not been tested in real trials for cramps during exercise. Current evidence points to tired muscles and the nerves losing control of them as the main cause. Stretching the muscle is the fastest fix during a cramp.
Is magnesium cream good for runners?
Many runners use magnesium cream for calf and foot massage and for spots that rub. Topical research is small, so use it along with sleep, food and easy days.
Sources
- Nielsen FH, Lukaski HC. Magnesium Research, 2006. PMID 17172008
- Volpe SL. Current Sports Medicine Reports, 2015. PMID 26166051
- Garrison SR, et al. Cochrane Database of Systematic Reviews, 2020. PMID 32956536
- Chandrasekaran NC, et al. Magnesium Research, 2016. PMID 27624531
- Schwellnus MP. British Journal of Sports Medicine, 2009. PMID 18981039
This article is educational and is not medical advice. Dr. Doug's products are cosmetic and are not intended to diagnose, treat, cure or prevent any disease.