A new study out of Belgium has shown that Covid-19 can makes sufferers’ muscles swell drastically. Yes, you read that right.

The researchers, who presented their findings at a recent virtual conference, discovered that some individuals with a severe case of the virus saw their muscle fibers balloon by over 60 percent while in the hospital.

So has a new, “sigma”, variant dropped?

Let’s find out.

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Massive muscles: an unexpected side effect of Covid-19!?

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Artist’s impression of the new sigma variant

Scientists believe the body’s immune response damages mitochondria, generally referred to as the “powerplants” of cells. As a result of this damage, water builds up in the cells, including muscle cells, causing them to swell.

Biopsies of the most powerful muscle in the thigh were taken from 18 COVID patients (average age 69, all men). They revealed that the muscles in four of them increased “massively” while in the ICU. The type 1 (endurance) and type 2 (explosive) fibers in these patients grew by 62 and 32 percent, respectively.

The discovery of this phenomenon stunned the Belgian team, since muscle shrinkage is generally more common among those forced to spend time in intensive care as a result of contracting the virus. Bed rest and mechanical ventilation often lead to muscle wastage, which can make recovery much harder and reduce quality of life for many years.

But gains-chasers should hold their horses.

As lead author Dr. Toon Mostien of Jessa Hospital notes, this kind of swelling can actually lead to muscle fibers dying. What’s more, this strange side-effect is almost certainly only a temporary result of the mitochondrial damage caused by the virus.

It’s also worth noting that type 1 fibers grew by 6% and type 2 shrank by 5% across all of the Covid-19 patients in the study, rendering the change statistically insignificant overall.

Indeed, when the study authors excluded the patients with severe swelling of their muscles, the remaining patients displayed significant muscle shrinkage. In patients without swelling brought on by Covid-19, their type 1 muscle fibers shrank by 11% and their type 2 muscles decreased by 17%.

Why you should be spending more time on your OHP

overhead press

Death and taxes, it is said, are the only certainties in this life. If you regularly lift weights, there is a third; someone will ask you, “How much do you bench?”

The bench press is comfortably established in the popular mindset as the strength lift. True connoisseurs would suggest that the squat or the deadlift should really take that title, but it is undeniable that the bench press is the rockstar of the big three.

But what if I told you that not only is the bench press not the most important lift you can do in the gym, it is also not even the best pressing movement?

Step forward, overhead press.


This new research built on previous work that showed muscle fibers could shrink by almost a fifth after a week in ICU.

“Although the results were not significant, a drop in perfusion of almost 10% could potentially contribute to muscle fiber destruction,” Dr. Mostien says in a media release.

“There are concerns that immune response to Covid can exacerbate muscle wastage, meaning that critically ill Covid patients experience more severe muscle damage than the general ICU population,” the study author concludes. “Given the global burden of COVID-19, it is vital we learn more about this and our research is an important first step.”

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