Energy is produced in almost every cell in the body.

Poor energy delivery results in physical fatigue. We all feel tired at the end of the day, but pathological fatigue is characterised by delay – overdo it one day and we ‘pay’ for it the next day, and possibly for several days. This is called ‘post-exertional malaise’. Part of the mechanism of this has to do with lactic acid. 

The dominant role of mitochondria is to produce ATP (adenosine-triphosphate). This is achieved (in normal circumstances) by oxidising or ‘burning’ acetate (derived from glucose and fatty acids) in the presence of oxygen. This is known as aerobic respiration. ATP is crucial to all body functions: it is the energy molecule and powers all such body functions. In good (normal) circumstances, the word equation for this process of aerobic respiration is:

Glucose + Oxygen → Carbon dioxide + Water + 32-36 molecules of ATP (aerobic respiration)

However, when one (anyone) has overdone things, then the system moves temporarily to anaerobic (without oxygen) respiration. For CFS, ME and LC sufferers, this switch to anaerobic respiration happens much more quickly than usual (for example, maybe walking five paces will cause such a switch) and also it takes much longer for the CFS, ME and LC sufferer to switch back to aerobic respiration (often days, if not longer). The problem with anaerobic respiration is that it only produces 2 molecules of ATP as seen in its word equation as below:

Glucose → 2 Lactic acid + 2 ATP (anaerobic respiration)

But it is worse than that, the lactic acid causes pain (the burn that athletes know so well) and also it takes 6 molecules of ATP to convert the lactic acid back to acetate, ready to be oxidised in aerobic respiration. One has effectively lost 4 molecules of ATP in this transaction. So, you are left with pain and a long recovery period from that pain.

I have written extensively on this subject and you will find the links to my three published papers here.

Poor energy delivery to muscles results in weak muscles with no stamina. Overdo things slightly and you get lactic acid burn. This is painful.

Many sufferers of CFS, ME and LC are convinced that they are developing dementia. Indeed, dementia is the symptom that occurs when energy delivery to the brain is impaired. It can be reversed by improving energy delivery mechanisms. We all know the symptoms: foggy brain, inability to concentrate or multitask and, sometimes, an inability to find the right word, or maybe use opposite words to those we intended, poor short-term memory and so on. Some individuals cannot even follow the plot of a film on TV. It is scary.

Low brain energy can also result in intolerance of light, noise, smell and sometimes touch. The business of processing information requires large amounts of energy. About half of the resources of the brain go into transforming the signal that arises from light on the retina to a three-dimensional depiction of the world around us. My worst afflicted patients only feel comfortable in a darkened room.

Then the brain gives us symptoms to stop us spending energy, such as depression (which makes us antisocial) and procrastination.

I think the symptom of feeling stressed is one that the brain gives us when it knows it does not have the energy to deal with demands.

Poor energy delivery to the heart manifests in two ways – with POTS (postural orthostatic tachycardia syndrome) and pain. Heart muscle pain is called angina.

The heart is a muscle – impair energy delivery and it can no longer beat powerfully. This presents with low blood pressure. I reckon a BP of 100/60 mm Hg or less is pathological.

There is much less work involved in pumping blood round the body on the flat, so the severely afflicted person spends their life horizontal. We all know this. We rest sitting down with our feet up. Problems arise when we stand up (the ‘postural orthostatic’ bit) – circulating blood in the vertical position means the heart has to increase output by about 20%.

However, our sick CFS heart cannot increase energy delivery mechanisms – it is already working to its full ability. The only way it can increase cardiac output in the short term is to beat faster (the ‘tachycardia’ bit). But beating faster is also demanding of energy; this is not sustainable. It beats less strongly, blood pressure falls and, unless our sick patient lies down quickly, they faint and drop unconscious.

This mechanism has been confirmed by Dr Peckerman who measured cardiac output by impedance cardiography and found that:

    …cardiac output in healthy people will vary from 7 litres per min when lying down to 5 litres per min when standing. In healthy people this drop is not enough to affect function. But in CFS the drop may be from 5 litres (lying down) to 3.5 litres standing up. At this level the sufferer has a cardiac output which causes borderline organ failure. In CFS the low cardiac output is caused by poor muscle function and therefore strictly speaking a cardiomyopathy. Tests of heart failure, such as ECHO, ECGs, angiograms and etc, will be normal.

The term ‘angina’ simply means pain in the heart. It is caused by lactic acid burn. The cardiologists recognise the clinical picture of angina as a result of poor blood supply to the heart when demands exceed oxygen delivery. There is a switch into metabolism without oxygen (anaerobic) and lactic acid is painful.

The patient with atherosclerosis (blocked arteries) immediately feels the pain, stops activity, and the oxygen supply is restored as demand falls and a normal mitochondrial aerobic engine clears the lactic acid. This takes seconds to minutes.

It is a very different picture for the mitochondria – that is, the CFS sufferer. They get lactic acid burn when demand exceeds energy delivery because the mitochondrial engine is slow – too slow even to clear the lactic acid. They suffer angina which lasts minutes to hours. They are dismissed with a negative angiography because the clinical picture does not fit imaging of the arteries (angiography) shows coronary arteries to be normal. They are now this is loan-shark pain – not a diagnosis, but a clinical picture.

At rest the brain consumes 20% of total body energy production, the heart 7% and the liver up to 27%. Much of this is to maintain our internal homeostasis (metabolic balance), including detoxification – that is, the clearing out of unusable/toxic substances that we take in and our body creates.

Poor energy delivery means we become slow detoxifiers and symptomatic of this is intolerance of drugs, including alcohol, antidepressants, statins and many more. Many patients are told that their symptoms can be improved with antidepressants, they then find they are intolerant of these, stop them and are accused of not complying with treatment. Further medical support may then be withheld.

Our immune system is our standing army with which we fight acute infection. Armies need white cell officers and soldiers with mobility, intelligence, communication skills, weapons and firepower. Having destroyed the enemy, our white cell troops then heal and repair the damage. These processes all require energy. Poor energy delivery is a cause of immune suppression. It may also lead to poor decision making, risking civil war (autoimmunity) or damage to non-threatening tourists (allergy).

If energy delivery to cells is slow, then organs go slow. Ultimately this leads to organ failure, degeneration and cancer.

All the consequences of poor energy delivery described in this article explain why improving energy delivery is the starting point for treating not just fatigue syndromes but all disease processes. My book, Diagnosis and Treatment of Chronic Fatigue Syndrome, Myalgic Encephalitis and Long Covid, describes the mechanisms of such poor energy delivery and how to fix them. We must understand the mechanisms in order to put them right.

• Chronic fatigue syndrome and mitochondrial dysfunction
• Mitochondrial dysfunction and the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
• Targeting mitochondrial dysfunction in the treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome – a clinical audit

This article has been created using extracts from Dr Myhill’s book Diagnosis and Treatment of Chronic Fatigue Syndrome, Myalgic Encephalitis and Long Covid. Both her book and website share a wealth of information with the book setting out a clear roadmap for recovery.

Dr Myhill kindly gifted a copy of her book to Living with ME in exchange for this article.