Welcome to Part One of the Peak Human Performance Guide. In this first part of the guide, we first take a look at the structure of the nervous system and its role in peak human performance. We'll explore the inter-operative and cooperative nature of brain and body function, the fundamentals of nutrition and sleep, and how these aspects cooperate to fuel and energise both cognitive and physiological performance. In performance settings such as in sports and work, we are at risk of a bias towards doing. We believe that if we work harder and longer, the results we want will eventually show up. But an immovable fact remains; no amount of effort in the wrong direction will bring about success. We must be smart, and create for ourselves the optimal environment for that success to occur. Understanding how the body and brain conspire to help us perform at our best is the foundation of that. If you want to create the optimal conditions for success in work and sport, part one of the Peak Performance Guide is the place to start.
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Introduction To The Brain & Nervous System
The Central Nervous System (CNS) is the site of an intense thunderstorm of bio-electro-chemical activity which appears to be the control centre of the human organism. Its nerve endings reach out through our extremities of sight, hearing, smell, taste and touch to act as the bridge between the environment and us. It gathers data, selects, sorts, discriminates, and transfers this information via bio-electrical signals to other parts of the body and the organism acts, for better or worse. We have conscious control over certain things, but most are handled automatically by the unconscious functions of the brain. Brain and mind are often used interchangeably, but they are not the same thing. In fact, the word “mind” may be a term so archaic and loaded with interfaces as to what it represents, it may be a completely unhelpful term to use when examining human psychology.
Research into the brain and the nervous system suggests that when we think, we do so with our entire body and not just our heads. The gut, for example, is as much involved in our emotional processes as the complex neural networks of the brain and central nervous system. You'll know this intimately from the sensation of butterflies in your stomach before an important work presentation or competition. There really is no separation of mind, brain and body – they are intrinsically connected and arise mutually in the human organism. However, our language suggests otherwise and often influences our thought about what is possible and what is not. Human beings are limited in physical reality and we cannot, for example, sprout wings at will and fly. But understanding how our bodies function and the environmental factors that influence it, we can improve our results at work, in business, and in sport.
Conscious and Unconscious Processes
As I write these lines I wonder how to phrase the ideas that occupy my thought. While there is no little me living inside my head directing things, there does seem to be some element of automation involved. Many behaviours and processes seem to operate without my intent. Blood pumping and lungs breathing, eyes seeing and ears hearing, operate below the level of awareness. They function without our will and we become aware only after the fact. Awareness itself So what exactly is the engine of these apparent processes? Where do the language I speak and the words I write live? Where are the pictures I see?
There are no easy answers to these questions. In fact, thus far in our scientific exploration of the nature of reality, it seems that there are no answers at all. All we seem to know is that the brain and mind constitute a complex and multifaceted arrangement of cognitive functions referred to in the literature as attention, perception, memory, thought, imagination and so on. Consciousness itself cannot be found in the brain. Perhaps we will need to drop the idea that it can, and indeed that brain matter somehow gave rise to consciousness. But that's not a discussion that we will indulge in here.
In this opening chapter of Peak Human Performance, we are concerned with how both brain and body interact and cooperate in the execution of high performance. The body directs the brain, the brain directs the body – it is one system. Considering this, there is little doubt that the body structure, nutrition, and recovery limit performance output. Sleep, the timing of meals, what food is consumed, levels of hydration and so on, have each been shown to have an influence on cognition and behaviour.
We will explore these and other factors affecting the brain and nervous system, closing with suggestions for how you can leverage these automatic brain-body processes, and as consequence, positively influence performance. Let's first take an overview of the human nervous system.
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The Brain And Nervous System
The human nervous system comprises two main parts; the Central Nervous System (CNS) and the peripheral nervous system (PNS). The CNS is the command centre consisting of the brain and the spinal cord, while the PNS consists of all the nerves that branch off from the spinal cord. The PNS is further divided into the somatic and autonomic nervous systems. The autonomic nervous system consists of the sympathetic and parasympathetic systems and is responsible for controlling all of the body's involuntary functions, such as heart rate, digestion, and breathing.
The sympathetic system is responsible for the stress response (fight or flight) and prepares the body for action by increasing heart rate, blood pressure, and breathing rate. It also causes the body to release energy stores, such as glucose and fatty acids, to provide fuel for strenuous activity. The parasympathetic system is responsible for the “rest and digest” response slowing heart rate, decreasing blood pressure, and increasing digestive activity. We will revisit rest-and-digest and fight-or-flight later in Part 5.
The Human Brain
The human brain contains about 1 trillion neurons working to coordinate sensory and motor activity in the entire body. Nerve centres function across two similarly structured hemispheres to control opposite sides of the body. Each hemisphere then is subdivided into the frontal, parietal, occipital and temporal lobes. It's worth noting at this point that these areas of the brain are not discrete. They, in fact, overlap in terms of function and in certain cases have been found to take up the slack where the brain has been damaged through disease or injury. It can be said that we use our entire brain for conscious and unconscious thought, and not as pop science suggests, merely 10%.
The Frontal Lobe is the area of the brain responsible for executive function and is associated with conscious decision-making, learning and planning. This area of the brain is particularly sensitive to dopamine, the endogenous neurotransmitter linked to feelings of happiness and elation which leads to reward reinforcement.
The Parietal Lobe is located above the occipital lobe and behind the frontal lobe and is responsible for interpreting somatic sensory information and perception and spatial navigation. For example, letting you know where your foot needs to be before striking the football, or where your tongue is as you chew your food so you don't bite it.
The Occipital Lobe is considered primarily responsible for visual data processing. is the smallest of the paired lobes of the brain and is considered primarily responsible for visual data processing. There are many sub-regions of the visual cortex which are specialised for different visual tasks, such as colour differentiation, and motion and depth of field perception.
The Temporal Lobe is central to auditory perception and is home to sub-structure circuitry critical to long-term memory and recall. The hippocampal region is critical for memory formation, and the surrounding medial temporal cortex is considered critical for memory storage. Recognition and processing of speech and music is also located here.
Neurons & Transmission In The Brain And Nervous System
Neurons are highly specialised cells forming the basic functional unit of the nervous system. The neuron consists of the cell body, dendrites, axon and terminal buttons. Synapses are the neuronal regions where the cells connect and transmit information to one another. More numerous by about ten times are Glia cells which surround and support the neurons. They comprise the myelin sheath which provides insulation much like the insulation on an electric wire, allowing for faster transmission between neurons.
Neurons possess the remarkable ability to process information and generate complex responses and behaviour in often unpredictable ways. Connections between neurons strengthen, weaken and change properties depending on signals received from the body's extremities and processing regions of the brain itself. Information processing is both linear and non-linear with neurons possessing the impressive capacity to adapt, self-assemble, auto-calibrate and manufacture chemicals required for healthy function. The result is that regions of the brain change according to the demands of the body in its environment.
Bioelectrical transmission throughout the complex neurocircuitry of the brain is fundamental to performance, but it is limited. Time, nutrition and energy availability restricts the transfer of signals in the brain. The brain is perhaps the hungriest organ in the human body consuming comparably more energy than the heart (Ames, 2000). An adult brain can account for 20% of all energy consumption. In babies, brain energy consumption is 60%, which reflects the demands of infant brain development (Hoffman, 1983). Of course, particular factors bear heavily on the efficiency of neuronal transmission in the human nervous system. Let's take a closer look at these.
Nutrition & Performance
The brain and body require a diverse range of nutrients to function and develop. Cognition is particularly sensitive to nutrition deficiencies and high performance perhaps even more so. Carbohydrates, protein, fat, vitamins, minerals and trace elements all play their part in peak human performance so getting the balance right is critical to producing your best.
Macronutrients
Macronutrients are so-called because the body requires them in large amounts compared to vitamins and minerals. They consist of carbohydrates (glucose), protein (amino acids) and fat (fatty acids).
Carbohydrates contain carbon, hydrogen and oxygen and therefore derive their name. The body absorbs both simple carbohydrates (glucose, fructose, maltose for example), and complex carbohydrates (starches for example) at different rates. Simple carbohydrates provide the quickest glycemic response and are the preferred source of energy by the brain. Complex carbohydrates are most abundant in the human diet. The body converts them into glucose and stores them as glycogen in the blood and muscle tissue available to fuel increased demand.
Proteins are a category of macronutrients formed by strings of chemical compounds known as amino acids and are a vital component in the growth, repair and development of the body and brain. They are particularly important in domains heavy on physical activity such as demanding stage performances and sport. The inevitable muscle damage resulting from physical exertion, for example, requires protein for repair and recovery. The human body constructs hormones and enzymes using proteins and they are necessary for digestion and the immune system.
Fats, also known as fatty acids, although the press demonises them, are beginning to find greater acceptance amongst performers and the general public. The reality is that fatty acids are an essential component in the diet of high performers. Fats are a source of energy that we require for nutrient absorption and assist us to maintain our body's core temperature. Essential fatty acids such as omega 3 are important for cellular function.
Water accounts for up to 75% of the human body and the average human being require between 2 and 2.5 litres of water per day to function properly. Athletes required probably twice that amount and often more depending on the demains of their sport and associated environmental conditions. Dehydration is detrimental to performance with psychological studies showing that mind dehydration (2%) result in reduced performance on physical, visuomotor, psychomotor and mental performance tests (Szinnai, 2005). Dehydration of even 1% has been seen to negatively affect concentration and memory and increase anxiety.
Micronutrients
The human body and its nervous system are remarkably capable of finding balance even when our dietary intake is less than optimal. Eventually, under the stress of poor diet, our bodies will begin to show cracks, but generally, it is immensely resilient to the abuses we inflict on it. However, if we wish to perform at elite levels in business, sport or the arts, we must give our bodies the best nutrition possible. And micronutrients play a critical role in the body's ability to perform at maximum capacity.
Underpinning efficient communication within the human nervous system are a variety of vitamins and minerals. They influence blood flow delivering oxygen and fuel to the brain and muscles, assist cell reproduction and the release and absorption of neurotransmitters involved in complex cognitive and biological function. Deficiencies in vital vitamins such as Vitamin A, B, C, D & E and calcium, and minerals potassium and sodium can limit blood flow and the brain's ability to communicate within itself and to the wider body structure.
Stuart Cotterill in his 2017 book Human Performance: Theory & Practice offers the following analogy; imagine you provide your brain with sufficient micro and macro nutrition through an optimised diet. Cotterill says it's like a fibre-optic broadband connection. Compared to a poor diet deficient in the necessary nutrients for high performance, the latter is like a dial-up connection.
Vitamins & Minerals Impact on The Brain And Nervous System
| Vitamins | Impacts |
|---|---|
| Vitamin B1 | Cognitive function |
| Vitamin B3 | Concentration, fatigue, headache |
| Vitamin B6 | Neuronal communication |
| Vitamin B12 | Memory, concentration |
| Vitamin C | Neuronal communication |
| Vitamin D | Cognitive function |
| Vitamin E | Cell membrane health |
| Minerals | Impacts |
| Calcium | Neuronal communication |
| Sulpher | Cell health, linked to depression |
| Iron | Cell development |
| Potassium | Neuronal communication |
| Phosphorus | Brain health |
| Magnesium | Deficiency can cause muscle spasm |
| Sodium | Essential for Neuronal communication |
| Table 1. |
Research on Nutrition & Performance
Although the relationship between food intake and performance behaviour is complex, the idea that nutrition has a measurable impact on cognition has had broad empirical support from psychological research (Cotterill, 2017). In addition to the reduction in cognitive impairment from an improved diet, scientists believe that nutrition helps bring performance above standard levels. Studies that examined the impact of breakfast on performance found that the absence of breakfast meals can lead to impairment of reaction time and short-term memory on cognitive tests (Smith, 1994).
And it doesn't only apply to professionals because school children's cognitive performance can also be hindered through the omission of breakfast meals (Chang & Walker, 1998). Kennedy & Scholey (2000) examined the effects of micronutrients and herbal supplements on performance. Smith et al. (1999) examined the effects of caffeine and other stimulants, and Messier (2004) in a review of recent studies showed how carbohydrates are a key component in the moderation of memory performance.
Always Test
The research is convincing, however, when applying the principles laid out here, we must caution against making blanket assumptions. Results may apply to the majority of people most of the time, but they may not apply to you specifically. So always make yourself the guinea pig in your own experiments. Trial a new idea for a while and if it fits your lifestyle, dietary requirements and produces desired results then keep doing it. If it doesn't then drop it and try something else.
That said, glucose is the favoured fuel source for the brain and without it, cognitive function suffers. If you can’t concentrate, you're irritable and you have blurry focus, then it’s likely you need a meal, or a rest or both. Smith & Miles (1986a) found that human performance follows particular rhythms throughout the day and following these rhythms is important. This might explain why some people perform better in the evening rather than first thing in the morning.
Our timing of meals and of what food those meals consist seems to be an important factor also. High, medium or low carbohydrate breakfasts do not improve performance according to a 1994 study by Lloyd, Green & Rogers (1994). However, they did find that mood was positively affected by the high carbohydrate breakfast. Fatigue and restlessness were also positively affected. Interestingly, high carbohydrate lunches appear to have a negative impact on performance when compared to high-fat meals, high protein, or no lunch at all. These and other studies suggest that what foods we consume and the time of day we consume them has a significant impact on performance.
Sleep & Performance
Findings of studies on sleep have broadly established that the function of sleep for the brain and nervous system and the entire organism, is restorative. Research shows that your brain activity, alertness and cognitive performance suffers from only one night of sleep deprivation. Sleep is also a biological necessity not only for the brain but for the entire body. Any of us knows that trying to function through the day, even when work processes are well established in our behaviour, can be very difficult without adequate sleep. Productivity, efficiency and safety can all be compromised.
From the point of view of performance at the highest level, Cotterill (2012) found that it is one of the most important factors in recovery, training and performance. Morin (2006) in a study on the psychological impact or insomnia, reported that the restorative nature of sleep is vital for coping ability, and adjustment to the physical, emotional and neurological stressors associated with daily work and other demands.
REM Sleep
Studies on sleep have reported two stages within the human sleep cycle; Rapid Eye Movement (REM) sleep, and non-Rapid Eye Movement (non-REM) sleep. REM sleep usually happens about 90 minutes after drifting off to sleep. The first period of REM lasts about 10 minutes with each subsequent stage getting longer. The final stage of REM sleep can last up to an hour. In REM, heart and breathing rate increase and intense dreaming occur. This is because the brain is in a similarly active state as when it is awake. Studies have shown that when we are under stress, we dream more and spend more time in REM sleep than non-REM. This is detrimental to recovery and can leave us feeling tired after a night's sleep.
During the deeper stages of non-REM sleep, the human body repairs itself, regrows tissues, builds bone and muscle, and strengthens the immune system. It's like the conscious waking self recedes into the background and the unconscious self can take over without hindrance. However, taking stress and anxiety to bed with us may impair this regenerative aspect of sleep. Therefore Optimal Sleep is critical for high performers.
Achieving Optimal Sleep
Sleep is essential for the proper function of the brain and nervous system. However, achieving a good night's sleep is often contingent on the place where we lay our heads. A familiar and comfortable environment is important, the absence of which can affect the amount and quality of sleep. In turn, this impacts psychological, emotional and physiological recovery (Samuels, 2008).
The inability to find sleep is classified in the research literature as insomnia, and defined by Roth (2007) as “the presence of an individual's report of difficulty with sleep”. Insomnia can be a real threat to performance and particularly so for those who travel in their business, sport or art. Therefore, it's effective when you establish routines and interventions that combat insomnia and sleep-related challenges. You can employ the following steps to enhance sleep.
- Only stay in bed for the time you are sleeping. In other words, for example, don't watch TV in bed.
- Don't try to sleep – it's counterproductive. Instead, read.
- Remove the clock from your bedroom. Set an alarm but leave the clock out of sight.
- Exercise in the evening.
- Avoid caffeine, alcohol and nicotine.
- Choose a regular time to bed and to rise.
Conclusion on The Brain-Body System
The relationship between brain and body is not in question. What is in question, however, for all performers at novice and elite level, is; how can I perform to my best? We have established in part one, the necessity for the brain to perform optimally as a prerequisite to performance at any level. Human performance is limited, but as athletes break records and business people become more innovative and creative, these limits are expanding. Fuelling the body and brain with optimal nutrition, and providing adequate rest and recovery is critical to growth, development and improved performance. Working diligently on these factors and seeking merely fractionally better outcomes, we may see improvements over time.
Read more about the human nervous system from the Noba Project from Portland State University
