Melbourne woman Irene Tey had so little energy after a bout of COVID-19 she couldn't even lift her arms to wash her hair.
"Things that you normally take for granted, like having a shower, at one point felt like climbing a mountain," she said.
"I had to resort to asking my partner to wash my hair for me because I literally had no energy to lift my arms up."
Ms Tey, a 36-year-old emergency department nurse, has long COVID.
She first contracted the virus in July 2020, and spent five days in hospital before recovering from her initial infection. But she still can't exercise or work a full day.
"It's not just the pure tiredness, it's as if I've run a marathon and my body's like jelly, my body has got no energy and walking feels like I'm wading through a pool of gel," she told the ABC News Daily podcast.
Irene describes "rollercoaster" symptoms that have meant she has had to adapt her daily expectations.
"Basic tasks at home, like vacuuming the whole house has become unachievable, even if I vacuum one room it will drain me of my energy for a long time," she said.
"Same thing with work, I haven't been able to go back to work at my previous capacity."
From her own account, Irene was fit and active before she contracted COVID-19 at work. She'd exercise six days a week, and trained in karate.
"I also deal with damages in my nerves, on my right hand — and I'm right-handed."
Many long COVID patients are physically fit, says expert
Dr David Putrino, an Australian researching long COVID in the United States, said cases like Irene's were common.
The majority of the 2,000 patients he is treating at a clinic at the Mt Sinai Hospital in New York were previously fit and healthy.
"Many were actively involved in recreational sport and engaging in incredible athletic feats like running marathons and exercising regularly, every single day," he said.
The physiotherapist, who has a PhD in neuroscience, said the average age of his patients was 42.
"Now, as a result of their long COVID symptoms, all of that has been taken away from them to the point where they're really struggling just to manage their daily life on a regular basis."
Dr Putrino has been recognised globally as a leading expert in the assessment, treatment and underlying physiology of long COVID.
He said the link between extremely fit people and long COVID was being found across the world.
"Many of the patients who are coming to us for care with long COVID symptoms did not report a severe course of acute COVID infection," he said.
"Then a few weeks after their last acute COVID-like symptoms resolved, all of a sudden these long COVID symptoms emerge."
Only a few studies have hinted at underlying risk factors
It's estimated that between 10 to 30 per cent of people infected with the coronavirus may develop long-term symptoms.
The condition bundles up a wide range of conditions, and not all of them are fully understood yet.
Crippling fatigue, brain fog, headaches, loss of smell and hair loss, along with other physically debilitating symptoms like vertigo, pain and numbness, and scarring of the lungs, are among the enduring symptoms.
"Of our most severe patients, we have individuals who are now bed-bound, meaning they're not really able to get out of bed without assistance," Dr Putrino said.
The phenomenon of long COVID is continuing to baffle the medical profession, and while fit people appear more at risk, it remains unclear who will and who won't end up with it.
"There have been a few studies that have hinted at maybe some underlying physiology, but they're not really too convincing at present, so we really don't have any risk factors for who's going to get long COVID and who isn't," Dr Putrino said.
"What we do know is that people who have long COVID are starting to show signs and symptoms that are consistent with people with autoimmune disorders, and so we do think that the immune system is at play here."
Dr Putrino described long COVID as an insidious condition that takes away a lot of an individual's life.
In the United States, the Biden administration has acknowledged long COVID as a recognised disability that is covered under the Americans With Disabilities Act.
St Vincent's Hospital in Sydney has this week launched a new long COVID clinic to treat Australians.
For now the treatment revolves around relieving patients' symptoms.
"We have found strategies for rehabilitation that help ease some of the more severe symptoms, and many of our patients gain significant function back, but many others even with aggressive rehabilitation do not fully recover, which tells us that there is still something going on below the surface that we need to address," Dr Putrino said.
His advice is to do everything to avoid contracting the illness, including getting vaccinated and keeping up to date with recommended booster shots.
There have been more than 487 million known COVID infections worldwide.
Irene Tey's symptoms have improved slightly, but she says the mental toll of having such long-term symptoms is difficult to grapple with.
"I felt lost, devastating loss.
"What can I do with my life?"
