Your Heart is a Muscle - and It Needs your Help

Your Heart Is a Muscle.

We all know our heart is a muscle, but it took me a while to think about it this way. It’s not a metaphor—it’s an actual, physical muscle and muscles have needs.

I’d been focused so hard on cholesterol and statins and blood pressure that I’d kind of forgotten about the mechanical side of the whole operation. The squeezing. The relaxing. The electrical signal that tells it when to do both, and the energy it burns doing that roughly 100,000 times a day without you thinking about it once.

What Your Heart Is Actually Doing All Day

Here’s the basic loop, in plain language.

Your heart squeezes and blood goes out. Your heart relaxes and blood comes back in. It does that over… and over… and over. And that squeezing and relaxing is triggered by an electrical signal that travels through the heart muscle in a very specific pattern. When the signal is clean and the timing is right, you get a normal, steady heartbeat. If something disrupts the signal—or the muscle can’t fully relax between beats—things start to go sideways.

Three things need to work together for this to happen properly: the electrical signal, the contraction itself, and the relaxation afterward. Most people think about the squeeze. But the heart fills with blood during the relaxation phase. If the muscle can’t fully let go between beats, it can’t fill properly—which means less blood gets pumped out on the next contraction. A heart that’s contracting fine can still fall short if the refill is compromised.

That’s actually a recognized clinical condition called diastolic dysfunction—some doctors call it “stiff heart.” Research in older populations has found diastolic abnormalities in as many as a third of people studied. It’s more common than most people realize, and it gets more common as you age.

Where Magnesium Comes In

For the heart specifically, magnesium supports a few things that matter a lot.

Muscle relaxation. When a muscle contracts, calcium floods into the muscle cells—it’s the signal that tells the muscle fiber to squeeze. When it’s time to relax, that calcium has to be pumped back out. Magnesium is what makes those pumps work. Without enough of it, muscles have trouble fully letting go. Think of magnesium as the off switch that calcium needs. That’s true for your calf after a long run, and it’s true for your heart muscle between beats.

Electrical signaling. Your heart has its own electrical system. And that system depends on charged particles moving in and out of cells in exactly the right sequence. Magnesium helps regulate this. When it’s low, the electrical system can become less stable, and research has consistently linked low magnesium to irregular heart rhythms. A review in the journal Open Heart noted that magnesium deficiency is implicated in a wide range of cardiovascular conditions, including cardiac arrhythmias.

Energy. Every cell in your body runs on a molecule called ATP which is basically energy currency (how your body captures, moves and transfers energy). And here’s the thing: magnesium is one of the required parts of how your cells actually put that energy to use.

Blood vessels. Magnesium helps them relax and open up normally. When levels are low, they can stay tighter than they should—and that’s one reason low magnesium is consistently associated with elevated blood pressure.

So Why Are So Many People Low?

 About half of Americans don’t get enough magnesium from food to meet basic daily requirements—and that’s according to the NIH’s own nutrition data. Some estimates put it even higher. And the number gets worse with age. Your body gets less efficient at absorbing it, and quicker to flush it out.

Magnesium is found in leafy greens, nuts, seeds, and legumes. Which sounds great—until you factor in that the mineral content of produce has declined significantly over the past several decades. In fact, researchers comparing USDA food composition data from 1950 to 1999 found reliable drops in nutrients across 43 crops. Modern agricultural practices, soil depletion, and crop varieties bred for yield rather than nutrition all play a role. In a nutshell, your spinach just isn’t delivering what your grandfather’s spinach did. And that’s not me being dramatic.

There’s also a catch with testing. Standard bloodwork checks magnesium in your blood, but most of the body’s magnesium lives inside your cells, not in the bloodstream. So levels can look normal on a routine panel even when you’re running low. If you want a more accurate read, ask your doctor specifically about a Red Blood Cell magnesium test. This will measure the amount of magnesium actually stored inside your red blood cells, rather than floating around freely.

So if you’re on a heart-healthy diet and eating all the right things—good. But it might still not be enough.

Then There’s the Energy Side of It

The heart is the most energy-hungry organ in your body. It doesn't get rest days.

Every heartbeat requires energy. In fact, heart muscle cells are packed with mitochondria—tiny structures that act like cellular power plants. And one of the key compounds those mitochondria depend on is Coenzyme Q10 (CoQ10). And this is where things get interesting. Statins work by blocking a specific step in the liver's cholesterol-production pathway. The catch is that the same pathway also produces CoQ10. So when statins reduce cholesterol production, they also reduce circulating CoQ10 levels as a direct consequence of how the medication works. Multiple meta-analyses have confirmed this effect. An updated meta-analysis of randomized controlled trials found that statin therapy significantly lowers circulating CoQ10, and earlier research across multiple trials has reported reductions in the range of 16% to 54%, depending on the statin type and dose.

Now, that doesn't automatically mean everyone on a statin will feel tired or develop muscle symptoms. The picture is more complicated than that. But because the heart and skeletal muscles are among the most energy-demanding tissues in the body, it's easy to understand why researchers have spent so much time studying the connection.

At the end of the day, your heart depends on a constant supply of energy to keep doing its job. And CoQ10 is one of the key players that helps make that happen.

So What Would I Actually Do?

As you know by now if you’ve read my other posts, I’m not a doctor. I’m a guy who had a heart attack at 47, went down a lot of research rabbit holes, and tries to share what I learned in a way that doesn’t require a medical degree to follow.

If it were me, the first thing I’d do is ask my doctor to check my magnesium level next time I get bloodwork. And I’d ask specifically — it’s not always on a standard panel, so you may have to push for it. Ask about that Red Blood Cell magnesium test if you want a fuller picture.

If you’re on a statin, it’s worth having a conversation with your doctor about CoQ10. There’s no official guideline saying everyone on a statin should take it. But there’s a solid body of research explaining why the levels drop and what that might mean for energy and muscle function.

And if you’re already eating well and still don’t feel like yourself? This might be part of the picture worth looking at.

Go read more about it and then talk to your doctor. But at least now you know the questions to ask.

Because you only get one heart.

Till next time, Stephen

Sources

DiNicolantonio, J. J., O’Keefe, J. H., & Wilson, W. (2018). Subclinical magnesium deficiency: A principal driver of cardiovascular disease and a public health crisis. Open Heart, 5(1), e000668. PMID: 29387426

Houston, M. (2011). The role of magnesium in hypertension and cardiovascular disease. Journal of Clinical Hypertension, 13(11), 843–847. PMID: 22051430

National Institutes of Health, Office of Dietary Supplements. (2024). Magnesium: Fact sheet for health professionals. U.S. Department of Health and Human Services.

Davis, D. R., Epp, M. D., & Riordan, H. D. (2004). Changes in USDA food composition data for 43 garden crops, 1950 to 1999. Journal of the American College of Nutrition, 23(6), 669–682. PMID: 15637215

Qu, H., Meng, Y. Y., Chai, H., Gao, Z. Y., Shi, D. Z., & Wang, W. T. (2018). The effect of statin treatment on circulating coenzyme Q10 concentrations: An updated meta-analysis of randomized controlled trials. European Journal of Medical Research, 23(1), 57. PMID: 30414615 

Marcoff, L., & Thompson, P. D. (2007). The role of coenzyme Q10 in statin-associated myopathy: A systematic review. Journal of the American College of Cardiology, 49(23), 2231–2237. PMID: 17560286