Historically, there has always been a view that there is a link between physical and mental well-being and vice versa. A great deal of research has been carried out into the relationships between various aspects of health including physical and psychological well-being over the years. There is an ever-increasing evidence base from multiple areas of research suggesting that physical and mental well-being are inextricably linked. However, there are numerous factors affecting health, and one could argue that there are multiple types of health or wellness. These can broadly be categorised as:-
|The interrelated aspects of Individual Health|
All of these types of health and well-being are interrelated, and the relationships are far from being fully understood. "Stressors" can take many forms and effect each type of health and thus overall health. Research has demonstrated significant links between various aspects of health. Hence, a pure BioPsychoSocial model of health is a little too simplified.
Elite Sports and Elite Military units have always appreciated the relationships between physical health, psychological welfare, and superior performance. Such organisations have invested considerable amounts of time, finance, research, and effort to ensure that they recruit, select, train and retain the very best candidates. In the case of the worlds elite military services, this includes individuals who are the best physically and psychologically suited to the demands of such a career. Diversity also plays a considerable part in the effectiveness of such Elite teams, with the selection of individuals coming from all walks of life, provided that they meet high and exacting physiological and psychological standards set by the selection course(s). Industry can learn a great deal from these elite level individuals and top performing teams. Such, organisations and cultures continually strive to push the limits of human and performance in general on a daily basis or as one now infamous British Military Unit would say, 'the unrelenting pursuit of excellence.' Even slight enhancements in performance can prove critical regarding winning and losing, or actual life and death. It is also of paramount importance that organisations get a good return on their investment. Such organisations fully understand the value of their people and the level investment in said people, hence utilisation and career longevity from these elite level personnel. Not only does physical and mental wellbeing have a direct impact on performance, but it is relatively easy to see the links between physical and psychological well-being.
As remarkable and as versatile as the human body is, the body does make various trade-offs. The human body has some extremely sophisticated systems, and yet these do not all need to be running concurrently and all of the time. Indeed, each system or process will utilise various resources and the human body only has finite resources and operates on an efficiency basis. Historically, multiple food sources would have been in short supply, and yet each bodily function consumes energy, various nutrients, and water. Examples of efficiency tradeoffs include the way the brains works, how we make decisions, how tissues within the body repair and how we deal with stress. Hence, the human body manages resources to be as efficient as possible, by moderating the level that various systems operate at and by turning systems on and off accordingly.
The human Central Nervous system (CNS) is made up of various parts, divisions, and sub-divisions. In simplistic, terms the “fight, flight or (freeze)” response aims to give a person or animal the best chances of survival in any, given perceived life-threatening situation. In essence, the body becomes turbocharged in preparation to “fight” or “flight” (run away), from a life-threatening situation. The “freeze” response is slightly different and is thought to occur due to the perceived life-threatening situation overwhelming a person or animals abilities or capacities to cope with the given situation. In some situations, people or animals will not "fight" or "flight" (run away), and will just “freeze,” much like a deer in the headlights. In some, perceived life-threatening situations the “freeze” response might work, but not in others could prove fatal. The physiological processes that enable/control the “fight, flight or (freeze)” response are related to the CNS. Physiologically, there are two particularly important parts of the Central Nervous System (CNS) involved in dealing with threats and repairing the body. These parts of the nervous system are part of the Autonomic Nervous System (ANS) and are called the Sympathetic and Parasympathetic Nervous Systems.
The hormonal release produces a large number of changes throughout the body, including shutting down the Parasympathetic Nervous System function. If one is about to have to "fight" or run away from a threat, then all resources need to be aimed at those activities and not digesting food, resting or procreating. The initial release of adrenaline and norepinephrine into bloodstream creates multiple changes within the body including, increasing heart rate, respiration, blood pressure, muscle tension and releasing stored nutrients and energy from tissues within the body. The increase in oxygen and nutrients within the blood supply to the brain heightens all five of the primary senses. The increase in muscle tension helps to protect the body from potential physical harm and also reduces blood flow to the superficial tissues (skin). Reducing blood flow to the superficial tissues would reduce blood loss should the person or animal get injured while dealing with imminent danger. The increase in oxygen, nutrients and energy supplies within the blood also primes the musculoskeletal system, to "fight" or "flight" (run away) from danger. The “fight, flight or (freeze)” response is so efficient that the human body has already reacted subconsciously before us consciously registering a threat. Which, explains why people can often get out of the way of danger before getting injured.
The second part of the “fight, flight or (freeze)” response is relatively instantaneous, but slightly slower than the initial reaction and enhances the primary response and keeps the body in a high state of readiness. The hypothalamic-pituitary-adrenal axis is responsible for the release and control of levels of cortisol in the bloodstream, via a negative feedback loop. The hypothalamus releases corticotropin-releasing hormone (CRH), which makes the pituitary gland release adrenocorticotropic hormone (ACTH). The presence of ACTH is detected by the adrenal glands and these glands then release cortisol into the bloodstream.
Historically there would have most likely been some form of physical activity straight after or shortly after the “fight, flight or (freeze)” process had been initiated, hopefully resulting in personal survival. Once a perceived threat to life has passed, then sensory inputs to the brain allow the brain to return the Sympathetic Nervous System to running at a base level. Blood cortisol levels would then be able to reduce via the negative feedback loop. However, the inhibition of this process during the “fight, flight or (freeze)” response, prevents cortisol levels from normalising. Under normal circumstances, the detection of high levels of cortisol in the bloodstream blocks the release of CRH and thus the release of ACTH. Which, in turn, results in a decrease in cortisol within the bloodstream. Importantly, the removal of the perception of a “stressor” stops the inhibition of the Parasympathetic Nervous System from functioning normally.
Hence, historically the chances of the SNS consistently activating would have been slim at best, meaning that the functions of the PSNS would have been able to operate on a regular basis. However, the modern world we live in today is hugely different to that of our ancestors. Today’s modern world has very different stressors, which are rarely life-threatening and yet the bodies primaeval response to stress is the same. Furthermore, the stress response can be initiated multiple times a day and even for extended periods of time. If the stress response is continually activated then the PSNS is continuously prevented from regulating critical metabolic processes.