I spent the first two weeks of January in bed, self-isolating in my room because I had tested positive for Covid. On day 11, I pulled on my trainers and decided to celebrate my new-found freedom with a jog around my local park.

Before Christmas, I had been building up my stamina slowly, but on my first post-Covid jog, I felt out of breath within 10 minutes and more than a little tempted to sack it off and go home. All of my progress, it seemed, had vanished.

“You decondition a lot more quickly than you think,” explains Dr David Salman, academic clinical fellow in primary care at Imperial College. Also, doing too much exercise after bed rest can affect your breathing and your musculoskeletal system – making it more likely you will sprain something, for instance.

That’s part of the reason why experts recommend a “phased” return to exercise following Covid-19, suggesting you, quite literally, walk before you can run. However, this isn’t just to protect you from a sprained ankle. “This approach is to make sure that the body’s immune system is not challenged too much too early,” says Dr Manoj Sivan, associate clinical professor in rehabilitation medicine at the University of Leeds.

If you had symptoms while you had Covid, “that means your immune system has struggled a little bit to manage this infection”, Dr Sivan says. You need to bear that in mind during recovery – even if you now feel fine. “Even though the person does not show symptoms any longer, we don’t know whether that immune system resets completely or not,” Dr Sivan explains. He recommends gradually increasing your level of activity.

If you over-do it too soon, you could delay your recovery. “When a person exerts themselves straight away to that [pre-Covid] level of activity, they run the risk of actually getting new symptoms and worsening their existing symptoms,” says Dr Sivan. “We believe that is because your immune system is not ready for that kind of challenge yet.”

Jumping back into your usual exercise regime before a full recovery also increases your risk of developing more serious illnesses like “post-exertional malaise” (PEM), according to advice published by the World Health Organisation. PEM can affect your energy levels, concentration, sleep and memory and can cause muscle and joint pains. If you experience it, you need to avoid strenuous activity and aim to conserve your energy.

Continuing to over exert yourself has other risks too. “After illness there’s a period where you’ve got to be very careful that you don’t challenge your immune system too much because if you keep doing it and you keep crashing, it might become permanently dysfunctional – and that is what is can lead to long-term problems like chronic fatigue syndrome,” says Dr Sivan.

How should we exercise safely after Covid-19?

Ideally, before you start exercise, you should aim to be asymptomatic for a week, according to the January 2021 study Returning to physical exercise after Covid-19, published in the BMJ. If you still have symptoms, Dr Sivan recommends you wait until your symptoms have been stable for seven days.

Once you are ready to return to exercise, you might consider following the WHO’s five-week plan, which gives examples of exercises you can do to build up your strength and gradually recover.

The WHO guidelines recommend using the Borg Rating of Perceived Exertion (RPE) scale – an assessment of how 
hard you feel you’re working on a scale 
from 0 (no exertion at all) to 10 
(maximum exertion). “It’s about perhaps staging your return to activity based on how you feel – and only gently incrementing it so you’re not pushing yourself too hard,” Dr Salman says.

WHO recommends you stay at each of the five phases for seven days and only move on to the next phase if you don’t experience any worsening of symptoms or “crashing”. If you experience excessive fatigue or breathlessness, Dr Salman recommends you move back a phase and take it easy.

Be alert to any “red flag” symptoms, 
such as: breathlessness when resting, 
chest pain, heart palpitations, dizziness, worsening “brain fog” or confusion, weakness in your face, arm or leg, or 
mental health issues.

If you experience any of these, WHO recommends you consult a healthcare professional.

How strictly should you follow the rules?

The WHO guidelines are just that: guidelines. While both Dr Sivan and Dr Salman agree that they are useful to follow, they acknowledge that they won’t be for everyone.

“There will be a lot of people for whom they’ve had minimal or no symptoms and they can retain the same levels of activity as they did before and this might not be as useful for them,” acknowledges Dr Salman.

If you have been asymptomatic, Dr Sivan says you might be able to return to baseline exercise. “If you were completely asymptomatic, I don’t see any point in changing anything - just continue on with what you were doing because you never had any symptoms,” he says.

Even if you had Covid-19 symptoms when you had the virus, you might not need to embark on a five-week program for recovery.

Whether or not you want to follow the WHO guidelines, “the key message is not to push oneself too hard and to take that graded pace”, says Dr Sivan. “Do the pacing [...] and self-monitor your symptoms and then take it easy and slowly progress back to what you were doing.”

Should you exercise if you have long Covid?

If you have had Covid symptoms for more than four weeks, you might have post-acute Covid (also known as long Covid). In this case, it’s even more important to pace yourself.

The CDC recently released its interim clinical guidance on long Covid, where it stressed the importance of rest and pacing. In this context, “pacing” refers to prioritising certain activities and delegating others or doing them on another day.

“I think pacing is a very sensible approach,” says Dr Sally Singh, professor of pulmonary and cardiac rehabilitation at the University of Leicester. “That doesn’t mean to say that you might not put in some exercise into your day, but it’s about selecting the activities that are important to you, looking at the time of day that you do them, building in adequate rest to your day and so on.”

Exercise can play a part too. “I think at the moment the research trials that are limited show that it is of value,” says Dr Singh, lead author of a May 2021 study that suggested regular exercise could aid the recovery of those with long Covid. The research, conducted by the National Institute for Health Research Leicester Biomedical Research Centre, followed 30 patients who took part in twice-weekly exercise over a six-week period. It found the six-week programme helped patients with breathing problems, fatigue and “brain fog”.

Dr Singh is keen to stress that this is not the same as “graded exercise therapy” - a controversial method with large increments in exertion that NICE no longer recommends for treating chronic fatigue syndrome. Dr Singh’s findings suggest a much more gradual approach. “You wouldn’t walk 10 minutes one day, think ‘actually I feel OK’ and then think, ‘tomorrow I’ll do 20’ because that’s a huge percentage increase. So people have to remember if they can only walk for 10 minutes, even walking for a minute more is a 10 per cent increase,” she says.

It’s not a one size fits all, however, and pacing needs to be individualised for long Covid patients.

The Daily Telegraph

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