Recently, there’s been a good amount of research studies being published about the difference in diet and supplementation practices between faster runners and slower runners, specifically in the marathon.
In essence, these studies are trying to answer the question:
Is there a link between the diets and supplements used by faster runners and their marathon performance?
And if so, what can we learn to better improve our performance?
The results were interesting:
- Faster runners consume significantly more calories compared to slower runners, despite weighing less, on average.
- Most of these calories came in the form of healthy fats.
- Faster marathoners consistently consumed or supplemented more magnesium than slower runners.
The findings on magnesium really stood out to me, so I wanted to investigate further to understand (1) why magnesium supplementation was so critical; (2) look at the performance benefits of magnesium; (3) and analyze what is the best way to take magnesium, including efficacious dosage.
Why Magnesium Supplementation Is Needed
Starting with overall data, it appears that magnesium is in the top 3 when it comes to common nutrient deficiencies.
In fact, studies show that close to 70% of the US population consume less than the required amount of magnesium.
This is likely caused by the fact that the magnesium we do eat from foods isn’t easily absorbed. Magnesium bioavailability appears to be in the 20-30% range.
For runners in particular, studies have shown that sweating significantly depletes magnesium levels. One study showed that as much as 12% of daily magnesium loss could be attributed to sweat loss.
Numerous studies have also demonstrated that serum magnesium concentrations in marathon runners immediately following a race were significantly lower than prerace values due to sweat loss (and again could contribute to cramping issues many marathoners face.
This data alone makes it pretty clear that magnesium deficiency is a common issue for runners.
Performance Benefits of Magnesium for Runners
So, now that we know why magnesium might be the critical missing supplement, let’s look at how magnesium actually benefits running performance.
Recovery from Workouts
The literature has demonstrated that magnesium supplementation can help runners recover in a myriad of different ways – from injury prevention to improved sleep.
Looking directly at post-workout recovery, a 2019 study on biomarkers of exercise damage (inflammation, creatine kinase, Interleukin-6) measured the speed of recovery between a control group and a group supplementing with 500mg/day after downhill running.
The authors concluded that magnesium supplementations significantly improved recovery times as well as reduced muscle soreness post-workout.
From the injury perspective, for runners who suffer from stress fractures, many studies have shown that magnesium supplementation can enhance bone mineral content, which can help strengthen bones and prevent bone-related injuries.
Indirectly, magnesium is likely best known for its ability to improve overall sleep quality by reducing cortisol levels.
Cortisol is your body’s main stress hormone and works to control your mood as well as your sleeping patterns.
The most common reason for elevated cortisol levels is stress, which can come from our daily work, family and other obligations.
Luckily, numerous studies have shown that supplementing with magnesium can lower cortisol levels and improve the length of time in a deep-sleep state.
This in turn helps maximize the recovery benefits of the sleep you are able to get, even when you’re not getting enough.
Magnesium and Testosterone Levels
Scientific research has uncovered evidence that low magnesium levels, especially in older men, may be connected to lower testosterone levels.
A 2011 study by researchers at the University of Parma in Italy demonstrated a strong correlation between magnesium levels and testosterone levels among almost 400 men age 65 or older.
In short, the higher the concentration of magnesium in the blood, the more testosterone each subject had.
Another study published by Vedat Cinar and colleagues in the journal Biological Trace Element Research examined whether increasing magnesium levels with a supplement had any effect on testosterone levels in martial arts athletes training for 90-120 minutes per day.
Cinar et al. found that the group who supplemented with magnesium experienced a significantly larger increase in testosterone levels than those who did not.
Now, testosterone is important here because it’s one of the most critical hormones we produce when it comes to exercise performance, helping improve both muscle strength and recovery.
Reduction in Cramping
While not all cramps are caused by nutritional deficiencies, some definitely are.
Thus, the fact that magnesium may help reduce cramping is an important factor in regards to potential performance benefits.
So, how does magnesium help prevent cramps?
Skeletal muscle, responsible for your muscle contractions, stores approximately 35% of the body’s total magnesium. The function of magnesium found in skeletal muscle is to work against calcium to prevent inappropriate firing.
As such, when serum magnesium levels are low, the chance of cramps increases dramatically. Supplementing with magnesium may therefore be especially important for marathon runners.
Training Performance
One of the main performance benefits of proper magnesium levels and potential supplementation is an increase in muscle oxygenation and aerobic capacity during high intensity exercise.
One study demonstrated that running, swimming and biking times significantly decreased when participants were given magnesium supplementation.
The data indicated that this was due to improved blood oxygenation.
Likewise, one study found that supplementing with 390mg/day resulted in an increased peak oxygen uptake and total work output during work capacity tests
In a similar study, supplemental magnesium elicited reductions in heart rate, ventilation, oxygen uptake and experienced “significant increases in endurance performance and decreased oxygen consumption during standardized, sub-maximal exercise” (i.e. running).
The consensus based on the scientific evidence thus far is that extra magnesium can enhance performance when supplemented in the 400-500mg per day range, especially in those athletes who are deficient or at risk of deficiency.
How to Supplement with Magnesium Effectively
If you’re looking to supplement with magnesium, you should aim to take 400-500mg daily with a meal, preferably in the evening as this will help more with sleep.
Selecting the right type of magnesium supplement is also important. You’ll want to take an organic form that contains all seven critical forms – chelate, bisgylcinate, oxide, malate, orotate, taurate and citrate.
Many cheaper supplements contain synthetic forms, which have low bioavailability and absorption rates, and only one or two of the critical forms.
Having all 7 forms of magnesium in your supplement is critical because each form “specializes” in helping a specific area.
For example, Magnesium L-threonate is best known for cognitive enhancement and orotate is best for recovery and athletic performance.
Here’s a full breakdown of the 7 elemental forms of magnesium if you’re interested in the details.
As such, my recommendation is Magnesium Breakthrough from Bioptimizers because it’s made with high quality, organic magnesium with no preservatives and contains all 7 critical forms. You can also use the discount code run10 to save 10 percent.
I’ve looked at a lot of different magnesium supplements and this is the one that best combines optimal dosage, all 7 critical forms, and doesn’t contain any filler.
Ideally, magnesium supplements should be taken separately to other supplements, but as we talked about in our iron and calcium supplement podcast episode with expert Pam Hinton, that can be almost impossible to take all the supplements on their own.
Some studies have found magnesium can have a calming effect on muscles, which may help with sleep. It is best to take with food, possibly with your evening meal, but just before bed can also be effective.
In short, based on all of the available research, adding a quality magnesium supplement with all 7 critical forms to your daily routine can be one of the easiest ways to improve sleep, recovery and training performance.
