What I've learned about Magnesium

I've been taking magnesium supplements for a week and a half now, and read a dozen articles on the Internet. Here's what I've learned, with strong confidence:

• You basically can't overdose on magnesium. You can, but the amount you would have to consume is prohibitive because the body will more or less just not digest it. It seems to pass through you like fiber, and give you diarrhea if you have too much. This is an important point because iron and caffeine are two other performance enhancers (in my definition of performance enhancer) and you can fatally overdose on them.
• Magnesium enables muscles to relax. It does not contract muscles or make them more powerful or help with oxygen distribution or dull the sensation of pain. The challenge I faced was that both my quads and hamstrings were probably locally short of magnesium so when I tried to step, I could not get either the front or back of my leg to relax when the other side was contracting and thus felt great pain trying to take every step. Similarly I vividly remember being on the table one time and one of the medical students, Katie, was trying to stretch me telling me, "relax" and I was screaming in pain, "I'm trying!" Yet I just could not. By the way, taking a magnesium supplement before going to bed is great, I have been sleeping so well!
• Number 569, Guiliana Frigero, is the one that suggested I needed magnesium at one point well into the darkness of the night as she walked past me, hours after I had been struggling to walk.

Roy Pirrung and  Guiliana Frigero, the woman who suggested Magnesium as she threw the hammer down passing me.

There are other potential benefits of magnesium, but the truth is, they are more contested and generally less well studied.

Maybe there is a placebo effect, but I have learned that if it works, it works, and magnesium has greatly helped my recovery. Talking to other ultra runners, I am not the first to have a magnesium shortage. At least, other ultra runners have felt much better after upping their magnesium consumption.

Relevant links:

Dr. Hyman's blog on magnesium and relaxation and doctors prescribing pills. 

WebMD's take on magnesium.

A Competitor article on magnesium.

To provide the opposing view that magnesium is not necessary: S!Caps.

An article about how difficult it is to measure magnesium in the body.