Motivation and emotion/Book/2023/Morning routine and motivation

Overview
 Tim is flying down the highway before losing control, swerving towards a tree, then BANG! Tim's alarm rings and he has now awoken. The time is 7:00am, work is still hours away and Tim still feels exhausted, so he scrolls through his phone while enjoying a sleep in. It is a cold winter day so Tim crawls out of bed, brews a hot coffee and enjoys a warm shower to kick-off the day. Tim hops in the car, the sun is low, so he slips on his sunnies and commutes to work. Throughout the day, Tim feels drowsy and struggles with motivating himself to work, before a hard crash in the afternoon destroying any hopes of productivity. Congratulations Tim, you have just fulfilled the worst possible morning routine.

Humans function on a 24-hour endogenous cycle, known as the circadian rhythm, regulating cycles of wakefulness and sleepiness throughout the day and night. Specific environmental and physical stimuli act as cues for the circadian rhythm, triggering an array of physiological processes with significant implications for mental states throughout the day. Many of the biological processes occurring in the human body are still being explored and understood, as the interaction of external stimuli and internal hormones and chemicals is exceedingly complex. However, a framework of knowledge currently exists, such that morning routines can be optimised to maximise the benefits of the various biological processes and align the body with the outside world. This chapter explores the endogenous physiological processes that follow a circadian rhythm and the influence of morning behaviours on the course of these processes.
 * Learning outcomes

This chapter aims to address the following learning outcomes:
 * 1) Outline humans' endogenous biological rhythm and physiological processes in the sleep-wake cycle
 * 2) Understand the influence of morning behaviours on these processes
 * 3) Provide an optimised morning routine to maximise the benefits of these processes

Circadian rhythm
Circadian rhythms are internal biological clocks that regulate various physiological and behavioural processes in almost all living organisms. Circadian rhythms follow a roughly 24 hour clock, synchronising with the solar day, and maintain the homeostatic sleep-wake cycle. Several external stimuli serve as cues for the circadian rhythm, known as 'zeitgebers', the most potent of which is the sun, while temperature, social activity, and exercise also provide influence. Accurate synchronisation with the 24-hour day ensures a range of physiological processes conduce with optimal timing, most notably inducing sleepiness at night and wakefulness during the day, but also regulation of temperature, metabolism, and the immune system.

The brain's timekeeper


The central pacemaker of the circadian rhythm is the suprachiasmatic nucleus (SCN), located in the hypothalamus. The SCN is a bilateral structure consisting of two nuclei, comprising around 10,000 neurons each. Multiple neuronal tracts project to the SCN, the most prominent being the retinohypothalamic tract (see Figure 1), which transmits information on light levels deriving from intrinsically photosensitive retinal ganglion cells (ipRGCs) in the eyes. The SCN interprets this information and conveys signals to other parts of the brain accordingly.

Sleep
The first and most critical aspect of a morning routine is waking time. It is no secret that achieving sufficient quality and quantity of sleep is imperative to a productive day, yet according to the Center for Disease Control and Prevention, 1 in 3 adults report not getting enough sleep every day. The National Sleep Foundation recommends 7-9 hours of sleep per night for adults (varying with age, see here for detailed list). The role of sleep is complex and still being understood in the literature, however much research has explored the biological processes that take place while asleep. It is during sleep that the body repairs and repletes cellular components necessary for biological functions that deplete through the day, a process outlined in Oswald's (1966) 'restoration theory'. It has been shown that sleep improves memory recollection, regulates metabolism, clears toxins from the brain, and reduces mental fatigue (Eugene & Masiak, 2015). Yoo et al. (2007) investigated the effects of sleep deprivation on brain activity and found significant alterations in connectivity with several brain regions. The results demonstrated reduced connectivity with the medial-prefrontal cortex (mPFC), a crucial brain region that integrates information from corticol and subcorticol regions and converses this information to output structures. Results also demonstrated increased connectivity with autonomic brainstem regions, further demonstrated to cause hyper-sensitivity to negative emotional stimuli. This study suggests that sleep may assist with both 'resetting' brain reactivity to emotional stimuli and in restoring optimal cognitive function, further strengthening the evidence of the restorative role of sleep.

Restoration theory
Dr Ian Oswald, a sleep researcher and psychiatrist, theorised that humans constantly expend energy through daily wear and tear, and one of the essential functions of sleep is to restore and rejuvenate the body and mind. Upon being deprived of sleep, individuals demonstrated reduced energy levels and motivation, poor memory and emotional regulation, and health problems like weight gain. Oswald suggested that sleep serves as a restorative process for the body and mind, essential to maintaining overall health and cognitive function. Further research building on Oswald's theory have demonstrated an array of endogenous restorative functions conducted while asleep.

Sleep cycles


A night of sleep involves a cyclical pattern between 2 major phases: rapid eye movement (REM) and non rapid eye movement (NREM). REM is the phase of sleep generally responsible for dreaming, characterised by increased heart rate and blood pressure (near that of waking levels), faster and irregular breathing, and arms and legs being temporarily paralysed. It is during REM sleep that information from the previous day is processed, consolidating important memories and regulating emotions. NREM sleep is subdivided into 3 stages, namely stage 1, stage 2, and stage 3. Stage 1 and 2 are the lightest stages of sleep, characterised by slightly slower breathing and reduced brain activity, while stage 3 is considered the deepest stage of sleep and the stage in which the body undergoes rejuvenating processes like regrowing tissues, building bone and muscle, and strengthening the immune system (Alam et al., 2023). A complete sleep cycle lasts around 90 minutes in duration (see Figure 2), and waking up during this cycle interrupts the valuable cognitive and rejuvenating processes. Upon waking, the brain contains residual adenosine, an inhibitory neurotransmitter that promotes sleep. This results in impaired cognitive and sensory-motor performance immediately after waking, known as sleep inertia. Cognitive testing has demonstrated that waking up during REM sleep or stage 3 NREM sleep leads to more pronounced sleep inertia, lasting minutes to hours after waking (Hilditch & McHill, 2019), resulting in extended periods of drowsiness and inhibiting motivation and productivity.

Adenosine
Adenosine is a neurotransmitter that suppresses the nerve cell activity in the brain, causing feelings of drowsiness and promoting sleep. Adenosine derives from the molecule called adenosine triphosphate (ATP), considered the 'energy currency' of cells as it provides energy at the cellular level. As a person expends energy through the day, ATP is broken down and adenosine is released as a byproduct. It is why people feel more tired as the day goes on, with adenosine accumulating in the brain and increasing the drive for sleep. It is during sleep that adenosine is recycled in the brain, a key aspect in the restorative role of sleep, providing a feeling of refreshment in the morning. Sleep deprivation increases the build up of adenosine in the brain and inhibits optimal functioning throughout the day, resulting in reduced energy levels and motivation.

Maslow's hierarchy of needs


Abraham Maslow's (1943) Hierarchy of Needs is a psychological theory of motivation that presents human needs in a hierarchical structure (see Figure 3), such that physiological needs (biological requirements for survival) must be satisfied before higher, more philosophical needs related to self-actualisation become motivators of behaviour. While progression up the hierarchy is not strictly linear in fashion, the basic premise is that more fundamental, short-term requirements motivate behaviour, and upon fulfilment, higher-level needs become more salient. As a biological requirement for survival, sleep presents as a fundamental physiological need, and fulfilling sleep requirements is imperative before higher-level needs become motivators of behaviour. Other aspects of a morning routine that aim to increase motivation and well-being present at the top of the hierarchy as self-actualisation needs, promoting personal growth and the realisation of one's potential.

Sunlight
As the most potent zeitgeber, exposure to sunlight should be achieved as early as possible in the waking day. Sunlight serves as the primary external cue for the circadian rhythm and maintaining an efficient sleep-wake cycle, a process known as entrainment. Research has demonstrated that newborn infants develop the components of a circadian rhythm postnatally (Yates, 2015), indicating the importance of zeitgebers like sunlight. Further studies have demonstrated that the circadian rhythm begins 'free-running' in the absence of zeitgebers, oscillating at a period longer than 24 hours (Brown, Eichling & Quan, 2011) and desynchronising the circadian rhythm with the 24 hour day. The most commonly experienced phenomenon regarding a sudden shift of the circadian rhythm is known as jet lag, characterised by a range of symptoms regarding sleep disturbances, fatigue, mood dysregulation, and digestive issues.

Cortisol
Cortisol is a steroid hormone produced by the adrenal glands, most commonly in response to stressors, deriving the term 'stress hormone'. Through its influence on metabolic processes, increased cortisol prepares the body for stressors by increasing energy and redirecting blood to essential functions. The body receives a natural cortisol boost once every 24 hours, theorised to prepare the body for anticipated stressors by promoting wakefulness and alertness. Although this cortisol boost occurs naturally, consistent exposure to sunlight will anchor it to the period of sunlight exposure and set levels of alertness, focus, and mood in motion.

Mechanism
Cortisol levels are regulated by the hypothalamic-pituitary-adrenal axis (HPA), by which a chain reaction of hormones travel from the hypothalamus, via the pituitary gland, to the adrenal glands. Several forms of stimulation trigger this reaction. Signals from the amygdala that indicate a danger or stressor initiate the 'fight or flight' response, activating the sympathetic nervous system and simultaneously releasing epinephrine (adrenaline) and cortisol from the adrenal glands. Evidence suggests that thermal fluctuations of the circadian rhythm serve as stressors, triggering cortisol release (Castrucci, 2021), a process known as the 'cortisol awakening response'.

Function
Cortisol falls under a class of steroid hormones called glucocorticoids, which play a pivotal role in the metabolism of glucose, fat, and protein in the body. The secretion of glucocorticoids, such as cortisol, stimulate the liver to perform gluconeogenesis, whereby the liver releases glucose molecules from the liver into the bloodstream. This process provides an influx of energy to the brain, boosting cognitive function to respond to stressors and promoting wakefulness and alertness. In the 'cortisol awakening response', cortisol levels begin to increase prior to waking, and peak around 30-45 minutes after waking, marking an increase of 40-75%.

The 'circadian dead zone'
When sunlight exposure does not occur until later in the day it can no longer time the cortisol pulse, causing cortisol to spike in the afternoon. This causes the body's temperature rhythm to be shifted late, causing difficulties falling asleep and desynchronising the circadian rhythm with the solar day. This disruption of the circadian rhythm causes significant disruptions in a range of endogenous systems critical to motivation and well-being, and a late-shifted cortisol pulse is actually a signature of depression and anxiety, most notably in the etiology and prognosis of 'seasonal affective disorder (SAD). SAD a type of depression that fluctuates with the seasons, with symptoms generally beginning around autumn as the weather becomes colder and sunlight is less abundant, indicating the detriments of sunlight deprivation and a disjointed circadian rhythm.

Melatonin
Melatonin is a hormone produced by the pineal gland in response to darkness, hence being coined the 'hormone of darkness'. The role of melatonin is still not fully understood, however has been proposed to indirectly promote sleep by phase-advancing the circadian rhythm (Arendt, 2003), or by inhibiting the circadian drive for wakefulness (Scheer & Czeisler, 2005). Due to the sleep-promoting effects of melatonin, it plays a key role in the regulation of the circadian rhythm.

Mechanism
Upon receiving signal of darkness, the SCN stimulates the pineal gland, which begins melatonin production. Due to the pineal gland's light-sensing capabilities, it has been commonly termed 'the third eye'. Upon receiving signals of darkness, a cascade of enzymatic reactions occur in the pineal gland that convert serotonin into melatonin. Upon exposure to sunlight, the SCN signals the pineal gland to cease melatonin production.

Function
The presence of melatonin in the brain does not directly induce sleepiness, but rather signals the body that it is time to transition from wakefulness to sleep. This acts as an assisting mechanism in maintaining an efficient circadian rhythm. In response to darkness, melatonin is produced and informs the SCN and body that it is night time, while in response to lightness, melatonin production ceases and the SCN and body are informed that it is daytime. One major drawback of the function of melatonin comes with the use of blue light emitting devices at night like smartphones. Exposure to blue light at night suppresses the binding of melatonin to receptors, causing difficulty sleeping and hindering the circadian rhythm's alignment.

Benefits of early exposure
As the most potent zeitgeber, exposure to sunlight is integral to the circadian rhythm through modulation of cortisol and melatonin levels. Sunlight anchors the circadian rhythm and entrains the brain to promote wakefulness and alertness earlier in the day, providing the cognitive tools for increased motivation and productivity. Research has also linked increased sunlight exposure with higher concentrations of both dopamine and serotonin in the brain (Sansone & Sansone, 2013). Dopamine, known as the 'molecule of drive', is a neurotransmitter that plays a central role in the brain's reward system, with the main role of driving motivation and pursuit. Dopamine reinforces behaviours that are pleasurable or rewarding and plays a key role in promoting both motivation and well-being. Serotonin is a neurotransmitter known as the 'feel good' molecule, acting as a natural mood stabiliser that improves happiness and well-being.

Temperature
Internal temperature plays a vital role in the optimal functioning of the brain and body both while awake and asleep and fluctuates on a circadian rhythm. A range of biological processes like metabolism, immune response, and muscle and brain activity vary in efficiency depending on core body temperature. Thermoregulation is the homeostatic process that maintains a steady core temperature despite changes in the external environment, ensuring appropriate variation and timing of core temperature.

Mechanism
Thermoregulation generally follows a circadian rhythm, but also comprises a complex system of feed-forward and feedback mechanisms to combat changes in the external environment. The preoptic area (POA), located in the hypothalamus, acts as the body's thermostat and sets a target temperature known as the 'set point', around 37 degrees celcius. The POA receives sensory input from a range of temperature sensors, called thermoreceptors, which are located in various areas of the body including the skin, viscera (internal organs like intestines), spinal cord, and the brain. When there is a discrepancy between actual temperature and the 'set point', the body initiates negative feedback mechanisms to reinstate the temperature to the set point. To increase temperature, this may involve shivering or increasing metabolic rate, and to decrease temperature, involves sweating or vasodilation, a process by which blood vessels near the skin widen and allow heat to radiate out.



Variation in sleep-wake cycle
Around 2 hours prior to waking, the body reaches its temperature minimum of a 24 hour day, between 1 and 3 degrees lower than the waking maximum. This decrease in temperature is a result of both the circadian rhythm signalling the body that it is time to sleep and the simultaneous slowing of biological processes like metabolism, muscle and brain activity, which generate heat with increased functioning. Prior to waking, internal temperature begins to increase and triggers the release of cortisol in anticipation of the waking day. Throughout the day, internal temperature increases to facilitate optimal functioning for temperature-dependent processes like metabolism, muscle function, and brain function, before decreasing in the evening as darkness ensues.

Cold showers
Aligning with the circadian fluctuations of temperature, behaviours aimed at decreasing internal temperature at night and increasing internal temperature during the day should be conducted. When thermoreceptors on the skin signal the POA that the surface of the skin is cold, the negative feedback mechanisms that combat a drop in temperature are activated, and core body temperature is increased. Furthermore, a sudden drop in skin temperature upon exposure to significantly cold water, around 15 degrees celcius or below, signals a threat to the body's internal temperature regulation and activates the sympathetic nervous system, responsible for the 'fight or flight' response. This activation results in the release of epinephrine (adrenaline) to prepare the body to respond to the perceived stressor, followed by a boost in cortisol to remain in a state of alertness. The sudden activation induced by a cold shower provides an array of benefits when employed in a morning routine. Most notably, the release of epinephrine and cortisol early in the morning propel the brain into a state of alertness, preparing the body for action by boosting metabolism and increasing blood flow, providing the brain with an influx of energy. This rapid energisation of the brain promotes optimal functioning and cognitive ability at an earlier point of the day, facilitating productivity and motivation.

Benefits of pain-seeking
Sramek et al (2000) conducted a study exploring the physiological responses upon immersion into water at different temperatures. Immersion into water at 14 degrees celcius, relative to water at 32 degrees celcius, saw a 350% increase in metabolism, 530% increase in adrenaline, and 250% increase in dopamine. Lembke (2021) expanded on the relationship between dopamine and acute pain, outlining that the same areas of the brain process both pleasure and pain, and achieves homeostasis by maintaining a balance between the two. The result is that pleasure-seeking activities that provide a rush of dopamine cause the body to decrease production or reuptake of dopamine to compensate. Contrarily, pain-seeking activities like cold showers provide a long-arc release of dopamine in an attempt by the body to feel better, increasing baseline levels of dopamine.

 In her book 'Dopamine Nation', Anna Lembke discussed a patient of hers who helped himself out of a cocaine addiction by taking cold baths. Drugs like cocaine function by binding to dopamine receptors, causing an abundant buildup of dopamine by preventing its reuptake. While the dopamine release following cold water immersion does not match that of cocaine ingestion, residual baseline levels are increased and the steep dopamine crash is averted. This reduces the motivational drive for a dopamine rush, facilitating motivation for healthier activities.

Exercise


Incorporating exercise into a morning routine provides a multitude of benefits for both increasing motivation and well-being. Early-morning exercise facilitates early exposure to sunlight and a long-arc dopamine release, but also clears out the inhibitory neurotransmitter adenosine. Upon waking, residual adenosine remains in the brain, and partaking in exercise early in the morning helps to clear out this residual adenosine. While exercising, blood flow increases, carrying waste products like adenosine away from brain regions. Exercise also stimulates the release of neurotransmitters like dopamine, serotonin and epinephrine, further providing mood-enhancing effects.

Caffeine
The most common method for combatting morning tiredness is consuming caffeine. The molecular structure of caffeine is similar to that of adenosine and is thereby able to bind with and occupy receptors that adenosine would otherwise latch onto, without producing the sedative effects. While this provides an effective short-term solution to residual tiredness after waking, increasing focus and concentration, the effects of adenosine are only stronger once the caffeine wears off. Once the caffeine loses its effect, adenosine binds to receptors with greater affinity, resulting in an afternoon crash. By delaying caffeine intake in the morning until adenosine is properly cleared out, taking around 60-90 minutes, the afternoon crash is averted, promoting wakefulness and facilitating motivation and productivity for a longer duration of the day.

The optimal morning routine

 * Set morning alarm at a 90-minute interval from falling sleep, allowing 7-9 hours of actual sleep
 * Achieve a minimum of 10-15 minutes of direct sunlight exposure as early as possible
 * Exercise in any form or intensity as early as possible
 * Take a cold shower, about 15 degrees celcius or below
 * Delay caffeine intake until 60-90 minutes after waking

Conclusion
Morning routines are integral to physiological and psychological states throughout the day. Despite physiological processes occurring naturally on a circadian rhythm, morning routines can be adapted to promote optimal timing and effectiveness of these processes. Reinforcing the circadian rhythm through entrainment and conducting pain-seeking activities early in the morning influence the hormonal and chemical processes that facilitate the sleep-wake cycle. Through a comprehensive understanding of endogenous physiological processes and their external triggers, morning routines are able to be optimised to promote daily motivation, productivity, and well-being.