I didn’t know anything was wrong during my workout—my first back at the gym since the start of the pandemic. Adrenaline was flowing, and I felt relieved to have returned to a regular strength-training routine after 14 months. Nor did anything feel out of whack as I stopped to dig into a plate of chicken shawarma on the way home (have to get that protein, after all). Or even the next day, when I woke up with what felt like a run-of-the-mill case of DOMS—delayed-onset muscle soreness—that “good pain” you often feel a day or two after a decent session.
But it became clear three days after my workout that all was not right. I couldn’t straighten my arms beyond about 65 degrees because the pain was too severe; if I forced them, they’d bounce right back up. It was painful to type at a normal desk angle, and to carry a light lunch bag. I was walking around, arms limp in front, like a T. rex. After my symptoms led me down a Reddit rabbit hole, I decided to get checked out. Reddit was right: I had a condition called rhabdomyolysis.
Rhabdomyolysis, or “rhabdo,” is a condition stemming from putting too much exertion on your muscle fibers, which can cause them to give up and break down, leading their contents to try and rapidly flush themselves out of the body, leaking into the blood in hazardously high concentrations. Most dangerously, the rush of myoglobin, a protein that carries oxygen within the muscles, can clog the kidneys—and in the worst cases, cause long-lasting kidney damage and even death. It’s been reported in complete novices to exercise as well as pro athletes, but the common factor is that it often occurs when starting or restarting exercise, leading experts to predict that as people flock back to the benches and machines post-vaccine, there may be a surge in these cases. Their warning: Go slow.
“I’ve been predicting for some time that when the gyms open up again, we’re going to see an uptick in rhabdo,” says Joe Cannon, a personal-trainer certifier with a master’s degree in exercise science. Cannon has written a book about rhabdo and hosts a podcast on which he interviews rhabdo patients. He does it, he says, to build awareness around a “strange phenomenon” that we know perilously little about. In his interviews with the rhabdo-afflicted, he hears three common echoes: one, “I’d never even heard of this before”; two, “the pain was excruciating”; and three, “I’m terrified to exercise again.”
“I’d never even heard of this”
Like me, you probably hadn’t heard of rhabdo, unless you have a medical degree or spend your spare time browsing bodybuilding forums. But it’s important for people to be aware of the syndrome, and its symptoms, as they return to their old exercise routines, which can be a cathartic outlet to the stress and anxiety of the pandemic. Here’s what to look out for: intense muscle pain, sometimes not kicking in until days after exercise, and the inability to move your body parts; it’s distinguished from typical muscle soreness by the pain lingering even at rest. Your muscles could appear swollen; some people experience nausea, vomiting, or fatigue. A telltale sign (though it didn’t happen to me) is cola-colored urine, evidence of the myoglobin trying to flush out of the system. Overexertion isn’t the only cause of rhabdo: It’s been noted among elderly people who take a fall, and victims of car crashes, drug overdoses, and snake bites.
As I went back to the gym, freshly immune, my concern was more about the minuscule chance of COVID-19 transmission, not kidney failure. Like many antsy homebodies, I had reached the momentous day of gym return after months of home workouts—resistance-band training in my living room, in front of Jeopardy!; on other days, high-intensity interval circuits, a combination of burpees, planks, mountain climbers, etc., while trying to not crash into my furniture. So I had not been inactive, by any means, but I’d done largely cardio-centric exercise with little heavy loading on any one muscle group.
Yet at my gym homecoming (gymcoming?), I was doing a routine of lat pulldowns, bent-over barbell rows, one-arm dumbbell rows, weighted lower-back extensions, reverse flies, and pull-ups. As was my previous custom, I did three sets of each, tending toward heavier weights as I went along so that the last couple of reps in a set of eight were deliberately labored. “That, to me, sounds like a classic trigger,” Cannon says. “Everybody’s a beginner when it comes to returning to the gym.” All those years building up strength means relatively little after a big break. “Even prior exercise is not a vaccine against rhabdo,” he says.
At the end of the painful fourth day following my workout, the local walk-in clinic told me to go to the emergency room immediately. There, a blood test showed that my levels of CPK, or creatine phosphokinase, an enzyme that leaks into the blood after skeletal muscle tissue is damaged (and so the prime indicator of the severity of rhabdo) had spiked from a normal range of 44-196 units per liter to 38,000.
I was fed three big bags of intravenous fluid through a drip. After a few hours, I was told I could go home—with the caveat that I drink three quarts (12 large glasses) of Pedialyte over the next 24 hours, and continue to hydrate for the days to come, to flush out the bad stuff. I later came to learn that another doctor’s opinion may have kept me hospital-bound for days on constant IV fluids. Depending on different evaluations, any case with a CPK level of 5,000 to 15,000 can be considered “severe.” Cannon says 38,000 is “definitely up there.” For him, there are no mild cases of rhabdo. “Is there such a thing as a mild case of muscle destruction?”
“The pain was excruciating”
Still, it could have been much worse. Cannon has seen cases where patients have CPK levels in the 100,000s. Thankfully, I didn’t get the darkened urine, or any kidney damage. Here’s what I did have, though: raised liver enzymes, because according to the doctor, the workout had also “cooked” my liver a little (not the verb you want to hear about one of your vital organs); seven and eight days following my workout, I had heart palpitations, before a further blood test told me this was likely because of dangerously low potassium, since rhabdo can disrupt your electrolyte balances.
And, the intense pain was not to be scoffed at. Body parts—like my T. rex arms—hurt because the muscles swell too much for the space they inhabit. That pressure buildup is called compartment syndrome, and if severe, it can cut off blood supply to the muscle. To treat it, a surgeon would have to “filet open your arm” (or leg, or calf), lay it open to release the pressure, and then sew it back up, says Maureen Brogan, a nephrologist and assistant professor at Albert Einstein College of Medicine in New York City.
In 2017, Brogan published a study on ER patients with rhabdo, detailing three cases caused by spin cycling. One 33-year-old woman on a free-class pass got rhabdo from just 15 minutes of exercise, and had to do months of physical therapy before returning to activity. Another woman, also 33 (incidentally, also my age), started vomiting two days after spinning. “Her legs were completely stiff,” Brogan says. “[She was] walking like Frankenstein.” Her CPK levels peaked at 80,000, and her strength didn’t fully return for five months. She suffered acute kidney injury and had to undergo a month of dialysis.
Save these reports, there is little aggregate data on the number of rhabdo cases, says Brogan, who perused all relevant literature for her study. There have been sporadic studies on rhabdo in college football players, in the military, and within police forces—one otherwise-healthy officer died after a 1.5-mile run. One 1995 figure suggested that the annual rate of rhabdo in the U.S. was 26,000, but Cannon is skeptical at the perceived rarity, reasoning that many cases go unreported. And that’s dangerous: Without medical care, sufferers may not know there’s potential internal damage associated with the presenting muscle pain. “I think it depreciates . . . how severe it can be,” Cannon says, noting it’s a “total body phenomenon” that can affect even heart rhythms and blood pressure.
“I’m terrified to exercise again”
Cannon says he’s anecdotally heard about more cases in recent years, due to those no-mercy workouts like spinning and CrossFit. Now, post-vaccine, he’s aware of more still. Brogan is also fearful of the looming trend: “It’s going to happen,” she says. “There’s going to be a spike.”
Cannon offers his recommendations for returning to the gym in a safe manner. For cardio buffs, he advises starting with a gentle 10 minutes on the treadmill, before slowly increasing the time on subsequent days to 15 or 20—but not increasing speed or incline until later on. Strength trainers should initially do circuit-style routines, lifting light weights with which they can manage 12 to 20 reps, slowly building up those reps, then adding sets—and only then increasing the weight. The idea is to build endurance first, before power and intensity. You’re also not overwhelming a single muscle group, which lifters tend to do, so no “arm day” or “leg day” for a while. Brogan adds: Don’t work out everyday at first. Stretch and, crucially, keep hydrating.
The same advice is true for people rehabbing from rhabdo, but only after they’ve been symptom-free for the time instructed by their doctor, which could be weeks or even months. The most disheartening admission Cannon hears is that the rhabdo-cursed are often squeamish about getting back to activity. You can certainly get it again, but “There is life after rhabdo,” he says. It just takes time and patience.
Ultimately, Cannon says, “I do think the best defense against rhabdo is education.” Brogan agrees, contending that companies that encourage extreme workouts like spinning or boot camps have a responsibility to give explicit warnings about rhabdo. And, they should probably be better than an old cautionary skit from CrossFit—which is more of a brag than a warning—in the form of a cartoon clown called Uncle Rhabdo, who wheezes while hooked up to a dialysis machine with workout equipment in the background. Though the circus character has since been buried by the company’s marketing, it still illustrates the tendency to trivialize the condition, or to put it down to an inadequacy of previous training.
I’ve certainly been guilty of subscribing to the “go hard or go home” school of strength training, where it’s not a successful session unless the last couple of reps are tough as hell and you need a spotter at hand. “This is going to hurt” was essentially the maxim of my friends’ workout circle some years ago. Even when I went to the walk-in clinic with rhabdo, I’d originally had other plans for the evening: work out again and just push through the pain. After all, what was the worst that could happen?