ReportWire

Tag: exercise study

  • ‘If Exercise Could Cure This, I Would Have Been Cured So Quickly’

    ‘If Exercise Could Cure This, I Would Have Been Cured So Quickly’

    [ad_1]

    In the weeks after she caught COVID, in May 2022, Lauren Shoemaker couldn’t wait to return to her usual routine of skiing, backpacking, and pregaming her family’s eight-mile hikes with three-mile jogs. All went fine in the first few weeks after her infection. Then, in July, hours after finishing a hike, Shoemaker started to feel off; two days later, she couldn’t make it to the refrigerator without feeling utterly exhausted. Sure it was a fluke, she tried to hike again—and this time, was out of commission for months. Shoemaker, an ecologist at the University of Wyoming, couldn’t do her alpine fieldwork; she struggled to follow a movie with a complex plot. She was baffled. Exercise, the very thing that had reliably energized her before, had suddenly become a trigger for decline.

    For the majority of people, exercise is scientifically, physiologically, psychologically good. It boosts immunity, heart function, cognition, mood, energy, even life span. Doctors routinely prescribe it to patients recovering from chronic obstructive pulmonary disease and heart attacks, managing metabolic disease, or hoping to stave off cognitive decline. Conditions that worsen when people strive for fitness are very rare. Post-exertional malaise (PEM), which affects Shoemaker and most other people with long COVID, just happens to be one of them.

    PEM, first described decades ago as a hallmark of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), is now understood to fundamentally alter the body’s ability to generate and use energy. For people with PEM, just about any form of physical, mental, or emotional exertion—in some cases, activities no more intense than answering emails, folding laundry, or digesting a particularly rare steak—can spark a debilitating wave of symptoms called a crash that may take weeks or months to abate. Simply sitting upright for too long can leave Letícia Soares, a long-hauler living in Brazil, temporarily bedbound. When she recently moved into a new home, she told me, she didn’t bother buying a dining table or chairs—“it just felt useless.”

    When it comes to PEM, intense exercise—designed to boost fitness—is “absolutely contraindicated,” David Putrino, a physical therapist who runs a long-COVID clinic at Mount Sinai, in New York, told me. And yet, the idea that exertion could undo a person rather than returning them to health is so counterintuitive that some clinicians and researchers still endorse its potential benefits for those with PEM; it’s dogma that Shoemaker heard repeatedly after she first fell ill. “If exercise could cure this,” she told me, “I would have been cured so quickly.”

    The problem is, there’s no consensus about what people who have PEM should do instead. Backing off physical activity too much might start its own downward spiral, as people lose muscle mass and strength in a phenomenon called deconditioning. Navigating the middle ground between deconditioning and crashing is “where the struggle begins,” Denyse Lutchmansingh, a pulmonary specialist at Yale, told me. And as health experts debate which side to err on, millions of long-haulers are trying to strike their own balance.


    Though it’s now widely accepted that PEM rejiggers the body’s capacity for strain, scientists still aren’t sure of the precise biological causes. Some studies have found evidence of impaired blood flow, stymieing the delivery of oxygen to cells; others have discovered broken mitochondria struggling to process raw fuel into power. A few have seen hints of excessive inflammation, and immune cells aberrantly attacking muscles; others point to issues with recovery, perhaps via a slowdown in the clearance of lactate and other metabolic debris.

    The nature of the crashes that follow exertion can be varied, sprawling, and strange. They might appear hours or days after a catalyst. They can involve flu-like coughs or sore throats. They may crater a patient’s cognitive capacity or plague them with insomnia for weeks; they can leave people feeling so fatigued and pained, they’re almost unable to move. Some of Shoemaker’s toughest crashes have saddled her with tinnitus, numbness, and extreme sensitivity to sound and light. Triggers can also change over time; so can people’s symptoms—even the length of the delay before a crash.

    But perhaps the worst part is what an accumulation of crashes can do. Rob Wüst, who studies skeletal-muscle physiology at Amsterdam University Medical Center, told me that his team has found an unusual amount of muscle damage after exertion in people with PEM that may take months to heal. People who keep pushing themselves past their limit could watch their baseline for exertion drop, and then drop again. “Every time you PEM yourself, you travel a little further down the rabbit hole,” Betsy Keller, an exercise physiologist at Ithaca College, told me.

    Still, the goal of managing PEM has never been to “just lay in a bed all day and don’t do anything,” Lily Chu, the vice president of the International Association for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (IACFS/ME), told me. In the 1960s, a group of scientists found that three weeks of bed rest slashed healthy young men’s capacity for exertion by nearly 30 percent. (The participants eventually trained themselves back to baseline.) Long periods of bed rest were once commonly prescribed for recovery from heart attacks, says Prashant Rao, a sports cardiologist at Beth Israel Deaconess Medical Center, in Massachusetts. But now too much rest is actively avoided, because “there’s a real risk of spiraling down, and symptoms worsening,” Rao told me. “I really fear for that, even for people with PEM.”

    There is no rulebook for threading this needle, which has led researchers to approach treatments and rehabilitation for long COVID in different ways. Some clinical trials that involve exercise as an intervention explicitly exclude people with PEM. “We did not feel like the exercise program we designed would be safe for those individuals,” Johanna Sick, a physiologist at the University of Vienna who is helping run one such trial, told me.

    Other researchers hold out hope that activity-based interventions may still help long-haulers, and are keeping patients with PEM in experiments. But some of those decisions have been controversial. The government-sponsored RECOVER trial was heavily criticized last year for its plan to enroll long-haulers in an exercise study. Scientists have since revised the trial’s design to reroute participants with moderate to severe PEM to another intervention, according to Adrian Hernandez, the Duke cardiologist leading the trial. The details are still being finalized, but the plan is to instead look at pacing, a strategy for monitoring activity levels to ensure that people stay below their crash threshold, Janna Friedly, a physiatrist at the University of Washington who’s involved in the trial, told me.

    Certain experimental regimens can be light enough—stretching, recumbent exercises—to be tolerable by many (though not all) people with PEM. Some researchers are trying to monitor participants’ heart rate, and having them perform only activities that keep them in a low-intensity zone. But even when patients’ limitations are taken into account, crashes can be hard to avoid, Tania Janaudis-Ferreira, a physiotherapist at McGill University, in Quebec, told me. She recently wrapped a clinical trial in which, despite tailoring the regimen to each individual, her team still documented several mild to moderate crashes among participants with PEM.

    Just how worrisome crashes are is another matter of contention. Pavlos Bobos, a musculoskeletal-health researcher at the University of Western Ontario, told me that he’d like to see more evidence of harm before ruling out exercise for long COVID and PEM. Bruno Gualano, a physiologist at the University of São Paulo, told me that even though crashes seem temporarily damaging, he’s not convinced that exercise worsens PEM in the long term. But Putrino, of Mount Sinai, is adamant that crashes set people back; most other experts I spoke with agreed. And several researchers told me that, because PEM seems to upend basic physiology, reduced activity may not be as worrisome for people with the condition as it is for those without.

    For Shoemaker, the calculus is clear. “Coming back from being deconditioned is honestly trivial compared to recovering from PEM,” she told me. She’s willing to wait for evidence-based therapies that can safely improve her PEM. “Whatever we figure out, if I could get healthy,” she told me, “then I can get back in shape.”


    At this point, several patients and researchers told me, most exercise-based trials for long COVID seem to be at best a waste of resources, and at worst a recipe for further harm. PEM is not new, nor are the interventions being tested. Decades of research on ME/CFS have already shown that traditional exercise therapy harms more often than it helps. (Some researchers insisted that more PEM studies are needed in long-haulers—just in case the condition diverges substantially from its manifestation in ME/CFS.) And although a subset of long-haulers could be helped by exercise, experts don’t yet have a great way to safely distinguish them from the rest.

    Even pacing, although often recommended for symptom management, is not generally considered to be a reliable treatment, which is where most long-COVID patient advocates say funds should be focused. Ideally, Putrino and others told me, resources should be diverted to trials investigating drugs that might address PEM’s roots, such as the antiviral Paxlovid, which could clear lingering virus from long-haulers’ tissues. Some researchers are also hopeful about pyridostigmine, a medication that might enhance the delivery of oxygen to tissues, as well as certain supplements that might support mitochondria on the fritz.

    Those interventions are still experimental—and Putrino said that no single one is likely to work for everyone. That only adds to the challenge of studying PEM, which has been shrouded in disbelief for decades. Despite years of research on ME/CFS, Chu, of the IACFS/ME, told me that many people with the condition have encountered medical professionals who suggest that they’re just anxious, even lazy. It doesn’t help that there’s not yet a blood test for PEM; to diagnose it, doctors must ask their patients questions and trust the answers. Just two decades ago, researchers and physicians speculated that PEM stemmed from an irrational fear of activity; some routinely prescribed therapy, antidepressants, and just pushing through, Chu said. One highly publicized 2011 study, since widely criticized as shoddy science, appeared to support those claims—influencing treatment recommendations from top health authorities such as the CDC.

    The CDC and other organizations have since reversed their position on exercise and cognitive behavioral therapy as PEM treatments. Even so, many people with long COVID and ME/CFS are still routinely told to blow past their limits. All of the long-haulers I spoke with have encountered this advice, and learned to ignore it. Fighting those calls to exercise can be exhausting in its own right. As Ed Yong wrote in The Atlantic last year, American society has long stigmatized people who don’t push their way through adversity—even if that adversity is a medically documented condition that cannot be pushed through. Reconceptualizing the role of exercise in daily living is already a challenge; it is made all the more difficult when being productive—even overworked—is prized above all else.

    Long-haulers know that tension intimately; some have had to battle it within themselves. When Julia Moore Vogel, a researcher at Scripps, developed long COVID in the summer of 2020, she was at first determined to grit her way through. She took up pilates and strength training, workouts she at the time considered gentle. But the results were always the same: horrific migraines that relegated her to bed. She now does physical therapy to keep herself moving in safe and supervised amounts. When Vogel, a former competitive runner, started her program, she was taken aback by how little she was asked to do—sometimes just two reps of chin tucks. “I would always laugh because I would be like, ‘These are not exercises,’” she told me. “I’ve had to change my whole mental model about what exercise is, what exertion is.”

    [ad_2]

    Katherine J. Wu

    Source link

  • Little-Used Fitness Measure Could Be Key to Exercise Results

    Little-Used Fitness Measure Could Be Key to Exercise Results

    [ad_1]

    Jan. 6, 2022 – There’s been a push in recent years encouraging doctors to prescribe exercise as medicine, telling their patients how often, how long, and how hard to work out to improve health.

    A new Brigham Young University study suggests doctors could take that initiative to the next level, prescribing exercise plans that result in a  specific health outcome; say, lowering your blood pressure or losing weight. 

    “The findings of this study, and others, suggest that we should be able to more consistently and accurately prescribe exercise like medicine,” says senior study author Jayson Gifford, PhD, an exercise sciences professor at BYU. 

    These exercise prescriptions would be tailored to patients based on a largely ignored fitness measure called critical power, or maximum steady state – the fastest you can go while maintaining a pace you can sustain for a long time. 

    By crafting workouts around critical power instead of the more frequently used VO2 max (maximum effort), we could more accurately predict health outcomes, just as we can with medicine, the researchers say in the Journal of Applied Physiology.

    “We’ve known for centuries that exercise is part of the way to develop a healthy and long life,” says Jordan Metzl, MD, a sports medicine doctor at the Hospital for Special Surgery in New York and author of The Exercise Cure. “But it’s only in the past 70 years that we’ve recognized the medicinal value of exercise.”

    Metzl, who was not involved in the study, helped develop an annual seminar at Cornell Medical School teaching medical students ways to prescribe exercise that go beyond the “30 minutes per day” cookie-cutter advice. Still, doctors and other health care professionals often struggle to prescribe exercise to prevent or treat disease. And a recent study from Oxford found that when doctors do give weight loss advice, it’s often vague and hard for patients to use. 

    “The drug of movement is one of the safest and most effective forms of preventive health,” says Metzl. “We need to get the medical community fully engaged in prescribing exercise for their patients.” 

    This study suggests that a focus on critical power could be key in making that happen. 

    What the Research Found

    In the study, 22 adults completed 8 weeks of either moderate-intensity training or high-intensity interval training, or HIIT.  The intensity levels specified in both plans were based on VO2 max. So, the people in the study trained at given percentages of their VO2 max.

    Both groups saw improvements in endurance, but results varied greatly from person to person. Those mixed results could be explained by individual differences in critical power. 

    “Improvement was much more correlated with the percentage of critical powers the individuals worked at rather than the percentage of their VO2max, like exercise physiologists have thought for years,” says lead study author Jessica Collins, a researcher at Brigham Young University. 

    Not only that, but several subjects who did not improve their VO2 max did see an increase in critical power and endurance. 

    “People tend to only focus on VO2 max,” Gifford says. “Many might see the lack of increase in VO2 max for some people and conclude that the training was ineffective. I personally believe that a lot of potentially useful therapies have been ruled out because of an almost exclusive focus on VO2 max.”

    Turns out, critical power varies a lot from person to person, even among those with similar VO2 maxes.

    “Let’s say you and Jessica had the same VO2 max,” explains Gifford. “If we had you both going at 70% of [your VO2 max], it could be above your maximum steady state, which would make it really hard for you. And it could be below her maximum steady state, which would make it easy for her.” 

    This means you are each stressing your body differently, and that stress is what triggers improvements in fitness and endurance. 

    “Below critical power, the metabolic stressors are well-managed and maintained at elevated-but-steady levels,” Gifford says. “Above critical power, the metabolic stressors are produced so fast that they cannot be controlled, and consistently accrue until reaching very high levels that cause failure.” 

    Knowing your critical power means you can predict how those stressors will build up, and you can tailor an exercise program that provides just the right stressor “dose” for you, Gifford says. 

    Such programs could be used for rehab patients recovering from a heart attack or from lung disease, Gifford suggests. Or they could help older adults improve endurance and physical function, Collins notes. 

    But first, researchers must confirm these results by programming workouts based on people’s critical power and seeing how much different measures improve.

    How to Find Your Critical Power

    Critical power is not new, but exercise physiologists and medical professionals have largely ignored it because it’s not easy to measure. 

    “People generally train off VO2 max or maximum heart rate, which is even less precise,” Gifford says. 

    Finding people’s critical power in the study involved multiple timed trials and calculating the relationship between speed/power and time, Gifford explains. 

    But for a rough measure of your critical power, you could use an app that measures functional threshold power (FTP), something Gifford refers to as the “Walmart version” of critical power. “It’s not exactly the same, but it’s close,” he says. (The app Strava features FTP as well as a pretty sophisticated power analysis.) 

    Or skip the tech and go by feel. If you’re below your critical power, “it’s going to be challenging, but you’ll feel under control,” Gifford says. Above your critical power, “your breathing and heart rate will continuously climb until you fail in about 2 to 15 minutes, depending on how far above you are.” 

    Still, you don’t need to know your critical power to start exercising, Collins notes. 

    “The beauty of exercise is that it is such a powerful drug that you can see benefits without fine-tuning the workout this way,” he says. “I would hate for this to become a barrier to exercising. The important thing is to do something.”

    [ad_2]

    Source link

  • Want to Tone Your Muscles? Try an ‘Activity Snack’

    Want to Tone Your Muscles? Try an ‘Activity Snack’

    [ad_1]

    Healthy snacks can be an important part of a nutritious diet, as small bites between meals can help keep our energy levels high. Turns out, our muscles may benefit from snacks too – “activity snacks,” that is.

    [ad_2]

    Source link