Skip Navigation

Post Covid Fatigue – my lived experience

As a doctor I have seen many patients over the years with some form of post viral illness or the more formally labelled ME or Chronic Fatigue Syndrome.  I’ve also known friends and acquaintances to suffer and seen close at hand how their it impacts their lives: a bewildering condition often with no known cause or recollection of any period of ill health and one that defies all efforts to combat it and return to normal.

Until now I have had no personal experience of the impact of a fatigue state. This has had me researching the literature to understand what we know about it and what mechanisms there might be to help it resolve.  I thought it might be worthwhile to give a brief insight to my findings and also explain my approach to dealing with it day to day in the hopes of a full recovery.

In mid-March I became unwell and tested positive for Covid-19.  My symptoms did not include any of the usual ones affecting the respiratory tract. I had no cold, no cough, no sore throat and no loss of smell or taste. I did have a horrendous migraine lasting five days accompanied by severe photophobia (light sensitivity) and dizziness; I had muscle tenderness and weakness and a burning sensation across the back of my torso. For five days I was pretty much on my back.  My symptoms resolved, some more rapidly than others. The burning sensation took about ten days to resolve at which point I also I tested negative. The headache and dizziness slowly petered out at about the same time. I remain sensitive to light although nothing like the same state I was at the onset.  As I started to try and return to normal duties I found that I was suffering from fatigue. Small, simple chores would be followed by an overwhelming physical need to lie down and maybe doze off for an hour. Added to this, whereas I had always been able to get up and start work as soon as I awoke in the morning, now it takes me about two hours to clear the ‘brain fog’ and become functional.

For those who don’t know me, my pre-Covid functional exercise level was considered to be unusually high.  As an endurance runner, I trained most days of the week whether out running, climbing hills or in the gym. My post-Covid state has been a stark contrast to this.

At the time of writing I am around ten weeks on and things are slowly improving. Initially every day was punctuated by puzzling episodes of fatigue. My sleep was also disturbed, probably as I was sleeping during the day. By the end of April, six weeks in, I could fairly reliably say that my stamina was improving and I could manage between six and eight hours of a day without dozing.  By way of example, in the second week of May I was examining students face to face at university. I had to ensure I was awake by 6am to give myself the required two hours to clear the brain fog before being able to get ready and then head to work. We examined from 9 until 5 with a couple of breaks. However, at the end of the day I couldn’t drive home and had to doze in the car for half an hour or so on before daring to drive.

Long Covid – Post Covid Syndrome

I think I can safely assume that I am suffering a form of post viral syndrome. I’m not sure whether this would be classed as ‘Long Covid’ but will use the terms interchangeably in this blog reflecting the use of these terms in the literature I have researched.

An ONS report dated 6th May 2022 states: “An estimated 1.8 million people living in private households in the UK (2.8% of the population) were experiencing self-reported long COVID (symptoms persisting for more than four weeks after the first suspected coronavirus (COVID-19) infection that were not explained by something else) as of 3 April 2022”.


At present there is no standard definition of Long Covid and researchers use between 4 and 12 weeks following infection with SARS-CoV-2 virus when conducting and reporting their studies.  On this basis, though it could be said I have Long Covid.

Two thirds of those affected, according to the ONS have symptoms which affect their daily lives.

In July 2021, The Royal Society of Medicine published a Review of Long Covid

In it they state that people suffering five or more symptoms of Covid-19 are likely to develop long term health problems which include: fatigue, shortness of breath, loss of taste or smell, muscle, joint or chest pain, cognitive impairment, memory loss, anxiety and sleep disorders. Fatigue is the most commonly reported symptom in post viral syndrome.

A considerable amount of research is ongoing in many countries to try and understand the mechanisms for Long Covid and thence to determine ways to treat it.

Myalgic Encephalomylitis and Chronic Fatigue Syndrome, ME/CFS

Long Covid is analogous to ME/CFS and these conditions have been extensively research over the years.  ME was first described in 1955 after an outbreak of a viral illness at the Royal Free Hospital where 200 people became ill and some had long term health problems. At the time no causative agent was actually identified but it was thought to be gastro-intestinal in origin. (ME implies an inflammatory process affecting the brain and spinal cord).

Whilst many people experience similar symptoms, each person’s experience of post viral syndrome, whatever label it is given, is unique to them.  As a doctor I heard many descriptions: from those who would seem to be able to function for a few weeks then relapse, to those who could describe having so many good days, some average and some bad days each week. Most people learned over time what their tolerance levels were.  Since suffering with it myself, I have also had quite a lot of people tell me that they have had episodes in their lives when they have experienced post viral symptoms and recovered; some after a few months, some after years, but a common theme seems to be about 12 to 18 months and those have generally been after having glandular fever as a child or in early adulthood.

Research and hypotheses

1.  Activation of Stressor Centre in the Brain. It is suggested that the virus acts as a severe physiological stressor acting upon an area of the brain called the Paraventricular Nuclei, PVN. It would do this by sending ‘stress signals’ by chemical messenger systems and or the nervous system and these overwhelm the stress centre. This in turn leaves the stress centre hypersensitive to all the ‘normal’ and everyday life stressors. The hypothesis then suggests that this could result in the reported post-exertional malaise episodes seen in both ME/CFS and Long Covid.

2.  Immunological hypothesis. Research is underway to investigate whether small fragments of the SARS-CoV-2 virus persist in the body long after a negative test when the immune system should have dealt with it.

3.  Abnormal blood clotting: Clotting dysfunction has been recognised from early 2020 as a significant pathological component of Covid-19 infection. More recently, a publication in Blood Advances on 11th May 2022 found that people suffering from long COVID may also face an increased risk of abnormal blood clotting. Investigators also found that this blood abnormality was four times more likely in those experiencing difficulties with basic exercise more than 12 weeks after their COVID-19 infection.

4.  A number of different viruses have been implicated as a possible causative agent for ME/CFS and one area of research has focused heavily on mitochondrial dysfunction.

Mitochondria are the ‘powerhouses’ of most of the cells in our body and their role is to produce energy but they are also involved in homeostasis, cell immunity, storing calcium for cell signalling, generating heat and play a part in cell growth and cell death. Cells have different numbers of mitochondria but some cells, our liver and muscle cells, for example, can have thousands per cell. They also have their own unique genetic material.

Intuitively, any dysfunction of mitochondria might be expected to lead to fatigue if they cannot produce the energy required of them for normal bodily functions. Imagine the weak glimmer of a torch light as the batteries are fading – well that’s how I felt in the first couple of weeks.

Viral infection leads to a loss of structural integrity and affects the function of mitochondria. It can also activate inflammatory factors which are thought may contribute to autoimmunity and persistent inflammation. The mitochondria themselves play a central role in the immune response to SARS-CoV-2 but this virus has been found to disable this initial immune response by the mitochondria. Other viruses that can also inhibit the response by the same method include Hepatitis C and B, Adenoviruses, Herpes Simplex 1, Epstein-Barr virus (Glandular fever), Cytomegalvirus and Influenza A, plus other coronaviruses. In this way these viruses can prolong their survival and evade the immune system enabling them to replicate and spread.

SARS-CoV-2 can hide and avoid detection in mitochondria and at the same time hijack the mitochondria and manipulate their function. In an uninfected state of operation, mitochondria would recognise if they were becoming unable to function normally and would ‘self destruct’. However, SARS-CoV-2 has the ability to interfere with this function too and prevent the mitochondria from undergoing death. Prolonging the number of dysfunctional mitochondria leads to a pro inflammatory state within the body and a chronic inflammation.

The detailed research is far more complex than I have sought to describe above.

Suffice to say that certain viruses including SARS-CoV-2 which causes Covid-19 are able to damage the function of our important mitochondria in multiple ways:

  • By damaging their structural integrity
  • Interfering with their ability to mount an immune response
  • Hijacking their usual function
  • The virus can hide inside the cells and avoid detection
  • Preventing their ability to self destruct when damaged

Mitochondrial response to exercise

Intuitively when it comes to fatigue as a symptom of post viral syndrome, finding ways to address and/or overcome mitochondria damage would appear to be a sensible way forward.

An understanding of mitochondrial response to exercise may be helpful. Many studies show the benefits of physical exercise on mitochondria. (There are too many studies to cite here but if interested please get in touch and I can point you in the right direction). A summary of findings:

  • Physical exercise allows the repair and elimination of damaged mitochondria and synthesis of new ones enabling recovery of the metabolic state
  • Physical activity triggers processes that regulate this turnover of damaged mitochondria and biosynthesis of new ones
  • Exercise improves mitochondrial quality and function
  • Exercise training promotes the degradation of abnormal mitochondria

We also know that muscle mitochondria have a half life of one to two weeks so once exercise levels fall for longer than that so will our exercise capacity as we become deconditioned.

My approach to dealing with my post viral syndrome

Armed with my newfound knowledge of possible mechanisms causing post viral syndrome/Long Covid plus my knowledge of how mitochondria respond to training, I decided the way forward for me was to ‘carefully’ try and ‘train’ my way through the fatigue and back to normal.

Thus, at a level very much lower than were I to be truly training, say for an endurance event, I started to increase time, frequency and duration in all my activities; this included time at a computer, conversation, reading, work, driving as well as walking, hill climbing, cycling and sessions at the gym.

I carefully monitor how I feel. I use various daily metrics such as resting heart rate and heart rate variability as a guide, alongside how I’m feeling to determine how much exercise, if any, to do and I will cut it short if my energy starts to wane.  Physical activity is taken at recovery level mainly and punctuated by lots of stops for food, fluid and photos or a chat with a someone. I’m pushing, or rather nudging, at those boundaries as I’m watching them increase, all the while being anxious that it could end in tears.

After any activity I am diligent with refuelling. Normally I’d be straight on with the next task but now I spend a few hours or even the rest of the day doing very little. That’s not me. In the early weeks I was needing to lie down and doze frequently but as I’m nudging forward it’s vegging instead of dozing.

So far my approach seems to be working as I am seeing signs of improvement. Having said that, I can still have an overwhelming bout of fatigue wash over me as it did one morning last week after preparing a meal at lunchtime when I just had to lie down and sleep for an hour. There was no obvious cause on that day.

Unfortunately, this approach does not seem to be having any effect on the morning brain fog. And, one thing I have failed to mention above is that I have currently lost my motivation to run!

During my literature review I also found suggestions as to diet and supplements which might be helpful but I choose not to include those here as I didn’t research them specifically and they may not have any scientific basis behind them. I may do some further work on this aspect of post viral research and produce a follow up item.

In the meantime, suffice to say a healthy diet with as many fresh vegetables and fruit as possible and elimination of processed food is recommended… by me. (I’m happy to have a conversation with anyone who might like to know more).

The future for Long Covid

Ninety Long Covid clinics have been introduced into the NHS and they are receiving around 5000 referrals per month. There is however, no treatment for Long Covid at present and physicians are simply trying to help people manage their condition on a daily basis.

In the meantime funding is being made available to further research the possible mechanisms for Long Covid and potential treatment options – all positive findings will hopefully help those with a post viral syndrome whatever label it is given.

One fact not to be overlooked is fitness level and to take account of the length of time I’ve been unwell and factor in that during this time I will have become de-conditioned. I can not therefore put any time projection on when I might be ‘match-fit’ again.


Each person’s experience of post viral illness/Long Covid/ME/CFS is unique to them. They may experience similar symptoms but in different ways at different times. There may be no pattern to it. They are likely to have tried every possible idea that is postulated as a potential treatment. For some it might work, for some it won’t.

I stress again that this is my experience and is unique to me. The approach I have taken is to follow the science as I see it and understand it.  While it seems to be working for me, it doesn’t mean it will work for others.




Imagine the unimaginable - then make it happen