I have to watch my magnesium. My body tends to get low on it, which destabilizes a lot of organs and makes bad things happen. So what about coffee? The beverage that washes out magnesium? The drink I love, and that is such a big part of cycling culture? How does one ride without it?
I mean, think of all the places where bicycles and coffee go together. We have bike shops that serve coffee. Roasters that produce Coffee for Cyclists. Weekend group rides always start with espresso shots at an open-early coffee shop. Heck, we even go on “Coffee Rides”, where we cycle from cafe to cafe, for cake and the inevitable cup of dark gold.
Coffee's a known performance enhancer in sports. 1
[M]ost researchers have found that caffeine simply spares muscle glycogen during endurance exercise. Glycogen is an energy source stored in the muscles. When glycogen runs low, the athlete is forced to slow down or stop. Anything that causes the body to conserve this precious fuel, as caffeine appears to do, allows an athlete to maintain a fast pace for a longer time period. For example, a study of cyclists reported a 20 percent improvement in time to exhaustion following two cups of coffee one hour before testing. The beneficial effects peak at about one hour after consumption and seem to last for three to five hours. [emphasis mine]
Joe Friel, The Triathlete's Training Bible, 3rd Ed.
But coffee's also detrimental to magnesium reserves. I watched an interview with a physician claiming that a single cup can wipe out as much as 350mg of magnesium from the body—the daily dietary requirement. Once you start doing any serious kind of sports, including cycling, requirements go way beyond that.
How do I know this? Last year I found out I had latent tetany. It's a condition where there's not enough magnesium in body tissues, resulting in a plethora of symptoms: losing consciousness, pain in the chest, back and abdomen, panic attacks, indigestion, nausea, heavy sweating, insomnia. The list goes on. Magnesium is involved in the works of pretty much every cell in the body.
My early symptoms included massive cramps in thigh muscles—both quads and hamstrings—starting after about 70km of cycling. Then came the heavy hit when I fainted one night. Shortly afterwards most of the other symptoms followed, which sent me to more doctors and tests than I had had throughout all my life. Thankfully, my neurologist had a hunch and sent me to the right test, because latent tetany is difficult to diagnose. It won't show on a regular blood test—only 1% of the body's magnesium is in the blood, the other 60% in bones, 29% in muscles and 10% in other soft tissues. There's no way to test magnesium level in tissues directly and latent tetany can only be diagnosed with an Electromyography (EMG) test.
I wasn't anywhere near a heavy coffee drinker up to that point. Two, occasionally three coffees a day was my norm—way less than many people I know. But different people have a different way of processing caffeine, different ways their body absorbs magnesium, and many people don't train as much as I do. So I had to work with what my body offered.
Coffee was part of my daily rituals. Get up, go training, have a rewarding cup afterwards. Have lunch, have another. I had to change those. Get out of the habit of pouring myself a cup in the morning. Talk myself out of it. Eventually, stop thinking about it.
I didn't break up with coffee completely. For one, decaf is fine. It contains much less caffeine, so there's much less harm to magnesium, and it still brings all the health benefits of coffee. Second, I celebrate having coffee much more these days. Every once in a while I'll go to a good coffee shop and have a treat. If I'm having fewer of these, I want every one to be excellent.
The baseline? Whether you're a coffee person or not, make sure you get enough magnesium. Getting it in your diet is ideal, but exceedingly rare, so add a solid supplement to what you're eating. And if you're feeling quirky, especially start having cramps where you didn't have them before, see a neurologist and ask them about tetany—the latent one 2.
In moderation, of course, and it's the caffeine that helps, but who would ingest caffeine without coffee? ↩︎
There's also a regular version of tetany, which is a heavy calcium deficit. That's the one most doctors seem to know about and I had many question my condition until I showed them the test results. ↩︎