Questioning Fatigue

It is worth questioning Fatigue

Whether you are sedentary or active, we rarely question fatigue even though it is what exists at the edge of our performance path. Like we often eat or drink without thinking much about the impact of our meals, how much could you be missing about fatigue that has an impact on your pleasure or internal growth? Perhaps a whole lot? Now, here is some structure to think it through.

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Parenting Message
Message for Geeks
Defining Fatigue
Why did I start thinking about Fatigue?
1234Healthspan Extension
1234Incorrect Focus on Fuel
Why should you think about Fatigue?
1234Networks & Links
1234Subtle Messaging & Mindfulness
Dimensions of Fatigue
Why should you address Fatigue?
1234Sedentary You vs Active You
Why you should NOT avoid Fatigue
Factors Driving Fatigue
Assessment and Biomarkers
Comparisons with Others
Engaging with and Mastering your Fatigue
1234Manoeuvre and Control
12345678Physical Activity
12345678Body-fat Control
12345678Endocrine System
12345678Autonomic Nervous System
12345678Smoking & Alcohol
Final Message

Parenting Message [top]

There are many parents who, when seeing a tired child, think that they need to feed them. They’ll stuff them with snacks of questionable quality as they ship them from music lesson to sports training. If you are one such parent, please read this article to understand that getting optimal results for your child in the long term does not rest on the single pillar of fuel. Of course, any fuel should also be optimal. [see High Octane Fuel to 110]

Your car does not break down because it runs out of gas!

Message for Geeks [top]

If you’re a geek like I am, and you too would prefer to be sedentary and go through large volumes of input material and produce large output too, the best thing you can do for a lifetime of quality output maximization is to master fatigue. That will not happen by being physically sedentary. Physical Fatigue and Mental Fatigue are inextricably linked.

Defining Fatigue [top]

In inanimate objects, fatigue is a state of weakness that appears over time, typically from external stresses. Think of collapsing old buildings or bridges…

In living creatures, very broadly, we use the same idea – a state of weakness that appears over time. The sources of stress can be external, but what we feel internally is fatigue. See Dimensions of Fatigue (below).

Fatigue requires the passage of time before it appears. What a system was capable of at the start at a certain quality of output is no longer possible.

Why did I start thinking about Fatigue? [top]

There are only a few parts to this story.

Healthspan Extension: Although most of my daily life is extremely sedentary, surrounded by science publications, financial models and computer code, every once in a while, I will do what we all should. I push my physical limits for a short period of time to extend my Healthspan. I feel moderate to extreme fatigue at times. [top]

Incorrect Focus on Fuel: I also noticed that often people will associate “I’m feeling tired” with the decision, “I should eat and drink to recover”. Nutrition is, however, only one item in the mental map of Fatigue. The biggest error people make is jumping to the conclusion that they are fatigued because they are low on fuel. The two can interact but they are totally different things!

The sedentary around the world die much earlier than they would like to, and this early death is most often associated with weight gain. Even those who make an attempt to have some regular exercise often do not get to their fitness goals; or they do not progress at a rate at which they would like to. Those who approach me for mentoring belong to both sets – sedentary and physically active – so as I continue to make progress with my own fitness year after year, it is important for me to have a broad and deep understanding of fatigue. [top]

110+: Being socially productive at 110 and beyond is only possible if I pay close attention to, not just performance, but also to fatigue. Many of my current personal projects are 20-year projects, some even longer. They are not the type of thing that I can afford to let be affected by short or long-term fatigue. But maybe avoiding fatigue isn’t the answer either to the question “How do I max out on life?” (The answer is below.) [top]

Why should you think about Fatigue? [top]

Sub-optimality: You can totally avoid fatigue just like you can avoid hunger. But just like avoiding hunger by eating mechanically every few hours without thinking about whether your food is working well for you, or whether you should, in fact, be fasting, there is suboptimality in not thinking about fatigue or attempting to avoid fatigue completely. [top]

Performance: At the edge of the performance path is fatigue. They are interlinked, twinned! So, it is unwise to ignore fatigue. [top]

Networks & Links: Although physical tiredness is what we first thing of when we think of fatigue, whether exerting physically or not, we all experience mental fatigue. In fact, physical and mental fatigue are intertwined too. Not surprising, of course – your brain is very much part of your body, and where most of your sensations of fatigue appear – and your nervous system is more important to your survival than your right bicep muscle. [top]

Subtle Messaging & Mindfulness:

Being disconnected from yourself is not a good thing. Your body is always sending you signals to think about. It’s worth listening to those signals and trying to understand what they are saying and why. Drowning out signals with caffeine, or just assuming that you need to eat immediately because you are suddenly hungry and tired will not necessarily be the best move. [top]

Dimensions of Fatigue [top]

Silos – Mainstream science thinks of fatigue as being mental and physical. In addition, we have emotional fatigue, especially considered when connected to trauma (e.g., death and divorce). Given that I believe we have health and fitness not just in our physical, mental and emotional dimensions but also spiritual, it follows automatically, that we get spiritually fatigued. [see Puru the Guru’s Wellness Tree]

Within the silo of physical health, I think of fatigue as being geographically local (arms tired of carrying shopping) or geographically global (the entire body is exhausted after many hours of gardening). [top]

Chronological – There is also the chronological time dimension of fatigue. Fatigue can then be thought of as being acute (i.e. short-term e.g. after a workout) or chronic (i.e. long-term e.g. for many common modern diseases). [top]

Biological – The biological time dimension of fatigue coincides with biological ageing. There are those who are chronologically young (50 years old) but fatigue easily (biologically old) and, yet, others who are chronologically old (90 years old) but don’t seem to fatigue even after many hours of manual labour (If you ever meet my Dad, ask him about his time travel!). [top]

Combining all of these dimensions, you could feel physical fatigue for a short period of time because of lifting a very heavy load repeatedly in a short span of time. Or you could experience problems with your internal biology because of the exhaustion of certain cells in your body over a long period of abuse through a poor lifestyle (e.g., diabetes!). [top]

Why should you address fatigue? [top]

Pleasure: If you are going to max out on life, especially when it comes to pleasure, you don’t want fatigue to affect your performance. Not in a single event, and not over a lifetime of events. [top]

Mental: Whether it is mental challenges (exams, delivering long lectures, being the last speaker of the day at a conference) you do not want your endurance to let you down because you did not understand fatigue. [top]

Emotional: If at the end of a business day you are routinely too tired to have an intelligent conversation with your parents or children and cannot be stoic when dealing with family issues, it’s worth considering what is systematically sub-optimal in your daily existence. [top]

ROTI: The fewer faults, errors and failures you have, the higher will be your ROTI over time. You will have fewer faults, errors and failures if you understand how fatigue impacts them. [top]

Volume: For a given ROTI, if you wish to invest more time into an endeavour to produce a larger volume of output, you will have to understand the nature of fatigue to proceed outside your normal output zone. Thinking about being productive at 110? [top]

Sedentary You vs Active You: This is about balance which is true mastery.

If you are more sedentary than you would like to be thanks to life’s many responsibilities, it will show up as early fatigue when you try to be active. Even when you are not active, you will perform at a lower quality and quantity than you would in a parallel universe with a more fatigue-resistant you. You don’t see that parallel universe, so you may ignore this performance issue – life then becomes sub-optimal. [Of course, you could choose to be willfully blind and pretend that ignorance is bliss. I wouldn’t choose that for anyone.]

If you are very active, in the extreme cases of chronic fatigue especially if you do a lot of sports, there is the definite risk of over-training which often leads to injury and temporary or permanent setbacks.

Clearly, what is needed is balance. Therein lies long-term optimality. [top]

Why you should NOT avoid Fatigue [top]

Shouldn’t you avoid fatigue? The simplest answer is, as usual, ‘it depends’.

If it is show time i.e. you are in the middle of a competition or flying an aircraft, or in the middle of a negotiation, the answer is ‘yes’. You do not want the outcome of the show to be sub-standard as the payoff can be large and negative.

If you are training and never get fatigued, that’s not a good thing. You have forgotten that Hormesis is your best friend. Your ROTI is likely to be tiny. So, now fatigue is desirable! The key thing is that it is under your control. Read: Internal Culture – Voluntary Hormetic Shocks.

If you feel very fatigued in every training session and your performance doesn’t seem to be improving, it’s quite likely that you are over-training. You don’t have mastery over your fatigue. You’ll need to cut back on your training volume, frequency, intensity or both.

If you are like me and don’t particularly enjoy exercise, you will increase your ability to have high mental stamina if you increase your tolerance to physical fatigue i.e., become fatigue resistant to most activities in your day. Read: Robustness, Resilience & Anti-fragility

Factors Driving Fatigue [top]

Physical: [top]

If we narrow in on physical fatigue and, specifically, on muscular fatigue, we can define it as the reduction of power when the muscle contracts. In that case we should bear in mind that failure at any of the sites between the brain and the cross-bridges in your muscle can contribute to fatigue. This can happen, loosely speaking, because of the various chemicals that are associated with the muscle tissue activity and those that are produced as output in the muscle tissue from the activity. Thus, either input factors can be limiting, or output substances can accelerate fatigue – or both.

Age & Gender – There is an observed association between age and fatigue. In general, children do not fatigue so easily, but their grandparents do. Although some women outperform men in ultra-endurance events, there is a tendency for women to experience fatigue more than men.

Health status: A very wide range of diseased states will result in early and frequent fatigue. Whether this is acute (e.g. a viral fever) or chronic (e.g. cardiovascular disease), there is a direct association.

[Read: Why you might run slower sooner than you think]

Mental: [top]

Your brain is a big energy consumer – even though the typical adult brain accounts for only 4% of body mass, your brain accounts for 25% of your body’s energy utilization in a typical day.

The volume and intensity of any recent physical activity will drive short term (acute) fatigue. Demanding physical activity will accelerate mental fatigue and it does not even have to be work you do with your limbs. Even digestion requires energy – something that is saved during short fasts or prolonged fasts. Of course, eating food will almost always leave you net calorie positive after accounting for the energy required for the digestion process. [see My articles on fasting]

Diseased states (typically associated with ageing and obesity or both) also tend to increase fatigue. If you are fortunate to interact with an elderly person who is disease-free you will notice that they do not fatigue easily, either physically or mentally.

Assessment & Biomarkers [top]

In a research scientist’s lab, looking specifically at muscular fatigue, evoked muscle responses are recorded via electromyography (EMG) electrodes placed on the muscle.  But you can tell when you are fatigued – that’s good enough! You don’t need a lab, but you can record information to understand your fatigue like a scientist might.

When I supervise blood tests of those I mentor, in addition to measuring markers of inflammation in the blood, I pay close attention to NOT inducing inflammation from intense exercise unless conducting an experiment to specifically look at inflammatory markers from exercise.

Comparisons with Others [top]

Comparing your fatigue with others is mostly a pointless exercise (pun!). There is somewhat of a genetic component to your fatigue resistance but the only thing that matters is what you can do to become a better version of yourself. If your lineage is from inherently lazy forefathers, don’t expect to make a mark on the world of endurance. What will matter for each of us is how we take the genetic material we’re endowed with and build upon that.

See: Competing & Comparing – Targeting Happiness Maximization.

Engaging with and Mastering your Fatigue [top]

With a long-term goal of a super-long Healthspan it should be clear that we need to engage with and gain mastery over fatigue. Without the right amount of fatigue over a lifetime, we do not reach our full potential. With too much fatigue, we get worn down and don’t reach our full potential. So, we need to experience the right type of fatigue, the right amount of fatigue, for the right reasons, so as to benefit from fatigue.

See: Your Wealth and Health – Robustness, Resilience and Antifragility
See Internal Culture – Voluntary Hormetic Shocks

You want to be fatigue resistant for most things in your daily life (think about the number of people who are biologically old because they get tired doing basic activities of daily living). At the same time, we need to engage in protocols that involve and include fatigue so as to reach that goal of a super-long Healthspan.

Monitoring [top]

You will fatigue at different rates from the different factors that drive fatigue. You will also fatigue at different rates in the different zones of the pathways where fatigue manifests itself. If your brain is ‘tired’ from a lot of mental tasks, you are likely to fatigue faster in a physical activity that doesn’t need you to think because the point of failure will not be that working muscle but closer to the source of the neurological signals! On the other hand, if you are mentally fresh in the morning and decide to set a personal record for pushups, the point of fatigue is likely to be the muscle itself.

Using fatigue as another dimension of self-exploration, it will be useful to be inward-focused to be vigilant of where you notice tiredness or a drop in performance. Along with this, it is important to be aware of the weakness bottleneck – you will fail at the point of your weakest link.

Measuring [top]

There are many aspects of your existence that you can be collecting data about to understand yourself better. Perhaps a personal fatigue score from 1-to-10 that you record could also be one such statistic.

Perhaps you can do this at 4 times: (i) when you wake up in the morning (ii) after a workout (iii) at the end of the day’s work and (iv) just before heading to bed. If that sounds too much to start with then, assuming you are fresh each morning, perhaps just record a score [a] after your workout [b] before heading to bed at night.

Manoeuvre and Control [top]

Because things within you are a connected network rather than isolated or fenced spaces, it is important to have a portfolio approach to mastering control of fatigue. It is also important to appreciate that sometimes what is optimal for short-term control will work against long-term success. For example, extra sleep is important when the body is fatigued, but sleeping for too long (loosely speaking) will work against you if you do it every night.

We are attempting to manoeuvre and control through the passage of time and although we like to have dates in a calendar, that make discrete jumps, your body flows from one sunrise to another. Whether it is sleep, physical activity or nutrition, you need to pay close attention to timing. The greater your attention to detail, the better will be the outcome.

Sleep: This is the most powerful tool for recovering from fatigue. It is not always easy to get right in an urban setting with work screens and TV screens, with artificial lighting and work, family and social pressures. Mastery of sleep is a bedrock of mastering fatigue. [top]

Nutrition: Even if you are hydrated well and not overweight, the wrong nutrition for your goals will lead to poor control of fatigue both during and after activity. Remember, nutrition is more than just about re-fuelling. Even if you are lean you can go for days without food (water-only fasting) and be mentally alert and physically capable. Typically, it will be the micro-nutrients, especially from plants, that will help you configure optimum recovery from short-term fatigue and long-term disease and ill-health.

[The dimension of nutrition for any specific health topic can always fill at least one thick book so, for today, let’s just say that your focus should be on anti-inflammatory foods, and foods high in antioxidants. That excludes paneer 😊 Read: The Paneer ki Sabzi Oxymoron] [top]

Physical activity: On any day with extra physical activity, you will notice accelerated fatigue relative to your normal sleep time. Of course, avoiding physical activity to avoid fatigue today will reduce your resistance to fatigue over the long term. You need to have careful progression along with remembering that Balance is True Mastery! [top]

Body-fat control: This can be beneficial in 3 separate and additive ways – dead weight, toxins and fat-adaptation.

To a first approximation, fat on your body is dead weight. That means every pound of extra fat relative to muscle mass will slow you down and make you fatigue earlier.

If you are overweight, your fat tissue produces harmful chemicals i.e. toxins (pro-inflammatory cytokines) that float around in your blood and also make you fatigue earlier.

If you engage in long periods of fasting and even do physical exercise in a fasted state you will be better fat-adapted. Then you will fatigue more slowly than someone who may be lean but isn’t fat-adapted. You can take advantage of this whether you are lean or overweight! It goes without saying, if you train yourself to be fat-adapted, you will find it very easy to lose body fat and be lean. [top]

Hydration: most often when you think you are tired or hungry, all you need is to ensure you are hydrated well enough. My sisters who fast during Ramadhaan will tell you how it’s not so easy to cook on those 30 days of dry fasting – not because of the lack of food but because of dehydration. See: Ramadhaan Running for All Faiths [top]

Endocrine System: all else being equal, your circadian rhythm will, in the absence of caffeine, make you feel a little more lethargic [approximately] between 10-11am and between 3-4pm. Use that knowledge to your advantage. [top]

Autonomic Nervous System: if you spend most of your typical 24-hours in sympathetic nervous system overdrive, you are likely to fatigue easily, perhaps be chronically fatigued, and are sure to have some undesirable health consequences over time. It is time you learned how to gain control of your autonomic nervous system (ANS) and spend more of your time with your parasympathetic nervous system dominating. [top]

Smoking & Alcohol: deserve a mention separate from Nutrition and Hydration. The advice for fatigue is simple – don’t! [top]

Boredom: as we get tired, our concentration drops, and we can feel bored. That boredom can mean you will not push hard enough and that will reduce your ROTI. Solution? Keep your time invested short but push yourself harder. Whether it is a mental or a physical task, you will benefit from the guidance in this. [top]

See Treadmill, Gym – Bored?


Final Message [top]

Hopefully, you were not fatigued when you reached the end of this article. I hope you will embrace and enjoy everything life has to offer, including periods of fatigue. If all this sounds complex, and you would like to be guided in detail to have the best life possible, you know how to reach me.



Dr Purnendu Nath spends his waking hours focusing on helping individuals and organizations reach their goals, to make the world a better place. He speaks, writes and advises on topics such as finance, investment management, discipline, education, self-improvement, exercise, nutrition, health and fitness, leadership and parenting.


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