Stress & The Training Process


*this is the first chapter from our restoration information packet 

This chapter is a gross over-simplification of what stress is, and how it affects the body.  Each definition and idea in this chapter has there own textbooks explaining them in detail.  My goal is to give you an elementary understanding of these topics by trying to explain the different types of stress and the various effects they have so that you may recognize why your body is responding the way that it is. 
A better understanding of stress and how it effects your body will help with how and why the rest of the information in the following chapters are relevant.  As well, and understanding of these allow for you to choose which restorative means can help with your stress related issue. 
Stress:
-       “Defined as an organism’s total response to environmental demands or pressures.” – Medical-Dictionary
-       The body’s rise to a challenge
Stressor:
-       Anything that throws the body out of Homeostatic balance
Homeostasis:
-       A state of equilibrium
-       The body’s internal environment that works to regulate and maintain variety of bodily functions within particular ranges in order to stay stable
Allostasis:
-       The process of achieving homeostasis through change
-       A process of management mobilizing energy to meet different demands
-       Different circumstances demand different homeostatic levels for different biological systems
Overtraining:
-       Stress that overreaches an individual’s recovery capacity
Hormesis:
-       Favorable adaptation to low level of toxin’s or stressors
Autonomic Nervous System:
-       Part of the Peripheral Nervous System
-       Responsible for regulation of the internal organs and glands
Parasympathetic Nervous System:
-       One of the two main divisions of the Autonomic Nervous System
-       Responsible for stimulation activities in the body to help it rest and conserve energy
o   “Rest and Digest”
o   Slowing down heart rate, lowering blood pressure, turning off the stress hormones, increase digestion, allows for fuel storage
Sympathetic Nervous System:
-       One of the two main divisions of the Autonomic Nervous System
-       Responsible turning on the bodies stress response in order to mobilize the nervous system for “fight or flight”
o   Increase heart rate, increase blood flow, dilates pupils, activates sweat glands, moves energy
-       It works to counteract the Parasympathetic System
Hypothalmic-Pituitary-Adrenal Axis (HPA):
-       A complex set of influences and feedback interactions between the hypothalamus, pituitary gland and the adrenal glands.
-       The HPA axis is a major part of the endocrine system that controls reactions to stress
-       Regulates many body process: digestion, immune system, mood, emotions, energy storage and expenditure
The Immune System:
-       Primary job is to defend the body against infectious agents such as viruses, bacteria, fungi and parasites
Lymphocytes:
-       White blood cell in the vertebrate immune system
o   Helps fight infections diseases and other foreign agents
-       Contain the T-Cells, B-Cells & “natural killer T-Cells”

Homeostasis - Allostasis
The fundamental role in the process of the stress response and adaptation belongs to the Autonomic Nervous System, and the Hypothalamic-Pituitary-Adrenal (HPA) Axis because they have an influence on every type of chemical exchange in the body in order to control homeostasis and protect the body from internal and external stress. 
Homeostasis is the body’s regulation to keep all biological systems stable while using the least amount of energy in order to survive.  (An example of this is the normal ranges of blood pressure level, body temperature, blood sugar level, ect.)  Homeostasis emphasizes that the body’s internal environment be held by the constant self-correcting actions of its organs.
Allostasis is the process of achieving homeostasis through physical and physiological changes.   While the body’s homeostatic systems try and maintain within narrow ranges (blood oxygen, body temperature, blood ph levels), Allostasis allows for broader boundaries.  These adjustments to changes are however twofold: turning on the Allostatic response, which most commonly involves the Sympathetic Nervous System and the HPA axis, and then turning off the Allostatic response.  Turning off the response allows for recovery and bringing the body back to its homeostatic level once danger has past.  In contrast, if the Allostatic response is not turned off, overexposure to stress hormones will result in negative pathophysiological consequences.[1]
An example of how Allostasis works in a short-term response to stress; if you are being chased by a dog, your body temperature raises quickly, your heart rate increases, your blood vessels widen and you start to sweat.  With the raising blood pressure, blood is being rushed through blood vessels with tremendous force so that it can get oxygen and nutrients to your working muscles and organs in order to save your life. 
In contrast, long-term exposure with the same Allostatic response begins to lend itself negatively.  Constant surges in blood pressure forcefully cause blood vessels to work.  In response, the vessels begin to build muscle around them making them more rigid.  More force is needed to send blood through them, thus increasing blood pressure even more.[2]  This can lead to tissue death due to lack of oxygen and blood supply to the heart.  Acceleration of atherosclerosis can increase the risk of heart attacks, and hypertension can develop. 
The price of accommodation to stress, the wear and tear that results’ in fluctuation of energy transportation and other biological systems accommodations, is called the Allostatic load.  It is fair to say that Allostasis is your body’s ability to adapt to stress in order to maintain and set a new level for homeostasis both in the short and long term.

Current Adaptive Reserves:
            The human body represents a biological system that has an interaction between two main energy flows:
-       Energy that is used for external work (running, lifting, jumping)
-       Energy to attain restitution ensuring adaption against stress

In conjunction with Allostasis, Adaptive Reserves is the energy in the body that is available for adaptation.  The amount of this energy available, the degree it is used, and the replenishment of it is based on many different factors that relates to each and every individual.  Therefore limits exit as to the human body’s ability to facilitate energy due to a finite amount that has its own threshold.  This threshold volume is limited based on the CNS and the HPA.  This mobilization of energy allows for the body to be very plastic and formable.  The more stress (continued volume & or intensity) that is placed upon the athlete, the more CAR will be used which will lengthen the time for replenishment, and also hardens the plasticity of the athletes CNS, shortening the longevity for adaptation.   “The development of the current adaptive reserve, therefore, may be the most important measure of the training effectiveness.”[3]

The Different Stress Responses:
When there is stress on the body disrupting homeostasis, the body will function in a non-specific manner (Allostasis) by setting a cascade of physiological responses controlling the quantitative aspects of the specific adaptation required.[4]  The magnitude of physiological change depends on the type, the intensity and the duration of the stress on the person.  This will either provoke an anti-stress or stress response on the body. 

Eustress / Anti-Stress / Hormesis
In the literature, eustress is defined as beneficial stress that produces growth.  A small dosage of, and or a short-term exposure to eustress has been found to heighten the body’s immune defense.  Hormones such as glucocorticoids and epinephrine rise in order to kill older lymphocytes (white blood cells) that don’t work well, and rush the healthy lymphocytes to the infection that allows wounds to heal faster and improving your immune system depending on the intensity of the muscular work.  This is why there is a lower rate of sickness among athletes as compared to the general population. 
This stress response will also raise your blood pressure, your heart rate, increase your breathing in order to accelerate getting oxygen and blood flow to divert energy and nutrients from storage sites in the body to your muscles and other areas that need it.  Due to this rise of energy, more oxygen and glucose are rushed to your brain enhancing learning and memory recall that allows for better processing of learning.  Your body’s long-term development like growth, digestion (constriction your stomach), reproduction, is halted so to allow the energy and hormones it needs to fight the short-term stressor immediately.  An example is when you are faced with a stressor, and “get knots in your stomach.”
“During an emergency, it makes sense that your body halts long-term, expensive building projects.  If there is a tornado bearing down on the house, this isn’t the day to repaint the kitchen.  Hold off until you’ve weathered the disaster.  Thus, during stress, digestion is inhibited – there isn’t enough time to derive the energetic benefits of the slow process of digestion, so why waste energy on it?”[5]
A term for Eustress in Toxicology and Biology is called Hormesis, which is used to describe as a relationship of a low dose of toxins and other stressors which have a favorable biological response.  The key features of Hormesis are the disruption of homeostasis with a modest overcompensation, a reestablishment of homeostasis and the adaptive nature of the body[6].  After a small stressor is applied, the resources in the body allocated for repair activities, but modestly in excess of that needed for the repair of the immediate damage.  This process will adapt the body against future stressor of this magnitude and help protect against a possibly larger stressors later on (CAR). 
An example of Hormesis is the use of Tylenol; too much will lead to an over-dose causing serious physical ailments or death.  A small dose relative to the individual will yield the pain blunting response they wanted.
“That which does not kill us makes us stronger, but less sensitive.”

Stress / Distress
            When the stress to the body is too great or goes on for too long of a time, the constant activation of the sympathetic nervous system begin to suppress the body’s defense mechanisms.  Stress will suppress new white blood cell formation and shorten how long the healthy lymphocytes stay in circulation, not only in the thymus, spleen and lymph nodes, but also in bone marrow as well.  This will begin to bring immunity below its previous baseline level.  An example of this can be seen during times of high stress, for instance when a student is in finals, or when they have major competitions coming up and they get sick.
The constant release of stress hormones such as epinephrine and glucoticoids begin to kill brain cells affecting the brains circuits, causing memory lose.  (Hence the old saying “stress makes you stupid.”)  Due to the continued activation of the stress response, the body’s constant mobilization of energy will begin to ware on the body and its energy storage.  You will fatigue faster, growth will be inhibited and you will be more susceptible to illness and disease.  (Increased blood pressure, diabetes, ulcers, and autoimmune-diseases.) “If you constantly turn off long-term building projects, nothing gets repaired.”[7]
So why doesn’t your body just leave your immune defense up at its enhanced level like during short-term stress?  Because it cost too much energy, and it will begin to make your defense system trigger-happy. (Autoimmune disease)[8]
 “If you constantly mobilize energy at the cost of energy storage, you will never store any surplus energy.  You will fatigue more rapidly, and your rise of developing a form of disease will even increase.”[9]


The Sports Training Process:
In athletic training, intensive muscular work has specific mechanisms for adaptation.  Because muscular work is catabolic (breaking down molecules into smaller units releasing energy) there is protein depletion in the tissues of the organs involved in the work and accumulation of metabolites provoking homeostasis disturbance[10].  After the catabolism has yielded, anabolic processes (the set of metabolic pathways that construct molecules from smaller units) begin to take place.  Protein re-synthesis begins with the elimination of metabolites, overreaching their contents in the tissues of the worked organs.[11]  The plasticity of the CAR will mobilize in order to allow recovery of the body’s functions up to higher level that will surpass the initial.
As briefly explained above, short term exposure to stressors can hence and improve the bodies defense mechanisms.  If the training stimulus is low enough and exposed to the athlete for a short enough time, it will yield a favorable adaptation (Hormesis) mobilizing the athlete’s adaptive resources.  With this constant exposure to short-term favorable stressors, mobilization of adaptive energy (Allostasis) will then activate specific mechanisms of the body’s adaptation process’s and defense systems.  These mechanisms assure the growth of specific protein synthesis of the working organs that will lead to a increasing of their functional capacity, thus raises the body to a higher homeostatic level.  Thus the more exposed the athlete becomes to the stressor, the higher the levels of stress will be needed to exceed homeostatic response in order to continue making improvements.  Genetically conditioned limits exit as to the amount of CAR as the athlete increases in age, amount of experience and sports mastery.  For example, this is why it is so harder for a professional powerlifter to increase his 1rep max in the bench press as compared to a 15-year-old boy. 
Short-term adaptation will transition into long-term adaptation gradually on the basis of multiple, short-term training stresses affecting the body by distributing the adaptive reserves causing the plasticity of the body to repair itself.  With the continued application of sports training Horemesis, long-term adaptive restructuring ensures. 


Overtraining:
The other end of the sword however, from an athletic development standpoint is that training stress that is either too high, and or exposed to the athlete for too long, breaching the CAR threshold, will eliciting an Allostatic load yielding negative consequences, exhausting the HPA axis, prompting illness and deceleration of recovery abilities. Immune defense is base mechanism of the process of adaptation[12].
 In the sports science literature, the body’s inability to handle the physical and psycho-emotional stress is often referred to as “overtraining.”  Overtraining can be presented in a several of different ways, depending on the part of the ANS that it is overactive:
-       Growth stops
-       Changes in appetite
-       Weight loss
-       General fatigue
-       Loss of vigor
-       Insomnia
-       Irritability, restlessness
-       Excitability, anxiety
-       Loss of concentration
-       Feelings of depression

“Well-planned training is characterized by the continued operation of eustress processes, whereas stagnation, soreness, and persistent minor injuries are early indicators of distress processes.” – Dr. Siff

The interesting part of how all of this information on stress is prevalent to athletic development is that whether the stress is physical or psychological, it is stress on the athlete.   Training is stress on the body, practice is stress, competitions are stress, school is stress, work is stress, and life is stress on the body! It is important when working with athletes to not simply look at applying more sets, more reps, more weights, more practices, and more competitions to the athlete in hopes that they improve. It is important to understand that stress can be a double-edged sword, and without an understanding of how stress affects the body you can easily end up “burning the candle at both ends.”

“The goal is certainly not to avoid stress – stress is a part of life.  It is a natural byproduct of all our activities…But in order to express yourself fully, you must first find your optimum stress level and then use your adaptation energy at a rate and in a direction adjusted to the innate structure of your mind and body.  It is not easy…it takes much practice and almost constant self-analysis.” [13]



[1] “Protective and Damaging Effects of Stress Mediators.”  Bruce McEwen PHD.  New England Journal of Medicine, 1998.
[2] The Great Courses - Stress and Your Body.  Dr. Robert Sapolsky
[3] “The Role of Specialized Training in Multiyear and Yearly Programs” Dr. Michael Yessis.  NSCA Jan-1983
[5]Why Zebras Don’t Get Ulcers.”  Dr. Robert Sapolsky
[6] “Defining Hormesis.” EJ Calabrese & LA Baldwin.  Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst.
[7] Why Zebras Don’t Get Ulcers.  Dr. Robert Sapolsky
[8] Why Zebras Don’t Get Ulcers.  Dr. Robert Sapolsky
[9] Why Zebras Don’t Get Ulcers.  Dr. Robert Sapolsky
[10] “General Adaptation Syndrome and Its Applications in Sports Training.”  2012.  Dr. Natalia Verkhoshansky. CVASPS 2012
[11] “General Adaptation Syndrome and Its Applications in Sports Training.”  2012.  Dr. Natalia Verkhoshansky. CVASPS 2012
[12] Supertraining 6thedition.  Dr. Yuri Verkhoshansky
[13] Stress of Life.  Han Selye. McGraw-Hill (1978)