Stress Hormones and How Your Body Physically Reacts to Stress

By Daniel G. Graetzer, Ph.D.
Faculty Member, School of Health Sciences

and Daniel J. Borowick, M.S., C.S.C.S.
2020 Sports and Health Sciences Master’s Degree Graduate

National Stress Awareness Month comes around every April, according to the American Institute of Stress. It is a reminder that an inability to handle high levels of stress, which everyone experiences at some points in life, can be extremely detrimental to your mental and physical health.

What Causes Stress?

Inappropriately managed or completely unmanaged stress impacts essentially all professional and personal areas of your life, such as:

• Employment
• Schooling
• Relationships
• Financial decisions
• Exercise and diet routines
• Your outlook on life in both general and in specific instances

Stress is also a strong contributing factor to addictions of all kinds. For example, some people resort to drinking more alcohol to relieve their stress.

The Body Reacts to Stress by Releasing Stress Hormones

To cope with stress, the body reacts by releasing a cascade of stress hormones that produce spontaneous but surprisingly well-orchestrated physiological changes. These physiological changes include:

• Elevated cardiovascular responses, such as a faster heart rate, increased cardiac output and a higher blood pressure)
• Tense muscles
• Deepened respiration
• Sweating
• Dilation of pupils
• Redirection of blood flow from the digestive tract to the skeletal muscles,
• A reduction in digestive system functioning
• A release of sugar from liver glycogen stores into blood
• A retention of urine due to a closure of the bladder sphincter

What Are the Stress Hormones in the Human Body?

There are three major stress hormones that the body releases during times of physical and mental stress:

• Cortisol
• Epinephrine (adrenaline)
• Norepinephrine (noradrenaline)

The release of these stress hormones can be either beneficial or detrimental to the human body, depending upon whether someone is reacting to actual or perceived stress, excitement, danger or physical exertion. What makes their effects good vs. bad appears to be the magnitude of their release and/or the length of time these stress hormones circulate in the bloodstream.

Cortisol

Cortisol is produced by the adrenal glands, which are positioned on the top of both kidneys. This stress hormone temporarily helps to reduce inflammation, control blood sugar, regulate metabolism and assist with memory consolidation.

Cortisol-mediated inflammation is important to short-term healing, but it is detrimental in the long term. For instance, the long-term elevation of cortisol from continual, overwhelming feelings of peril (such as someone confronted with a constant and deadly threat) is very detrimental to many body systems.

The release of cortisol and most other stress hormones is controlled by negative feedback loops. When the amount of cortisol in the body increases to an optimal level for a given situation, it is normally inhibited by the release of corticotropin-releasing hormone (CHR) and adrenocorticotropic hormone (ACTH).

Cortisol also has an effect on salt and water balance, which helps regulate blood pressure. Cortisol levels significantly increase in response to long-duration, high-intensity exercise, which indicates that exercise has a major influence on one’s level of inflammation, blood sugar regulation and overall metabolism (the use of food to create energy).

Epinephrine

Epinephrine is the main sympathetic nervous system “fight, flight, or freeze” stress hormone. It is commonly released in response to actual or perceived threats transmitted through nerve impulses that are sent from the brain to the adrenal glands.

Chromaffin (neurohormone-producing) cells in the adrenal medulla secrete epinephrine into the blood where it circulates to various locations to initiate various body responses. Epinephrine provides energy to major muscle groups and greatly increases one’s heart rate and blood pressure. Whether the stress originated from a life-threatening encounter with a grizzly bear or a recreational or competitive exercise bout, the body reacts by sending out epinephrine in the same way.

Norepinephrine

Norepinephrine is another stress hormone that is produced and secreted by the adrenal glands. According to Everyday Health, it plays an important role in the fight-or-flight response. It “also boosts alertness, arousal, and attention, and affects your sleep-wake cycle, mood, and memory.”

Epinephrine, Norepinephrine and Sports Performance

Ever hear the dramatic stories about a mother tearing off a car door following an accident which trapped her child inside or a child lifting a freezer that had fallen on their puppy’s tail? Epinephrine is the main power-packed hormone that stimulates the nervous and muscular systems in these situations.

While an appropriate release of epinephrine and norepinephrine is essential to optimal sports performance, a large uncontrolled high-voltage release of these catecholamines can be detrimental. For example, they can cause athletes to quickly lose their concentration and possibly their temper in the heat of competition.

As exercise intensity progressively increases to 60-75% of maximal capacity, epinephrine is progressively released from the adrenal gland, according to the American Council on Exercise (ACE). Epinephrine has several important cardiovascular functions during exercise, including stimulation of a controlled increase in heart rate, cardiac output and blood pressure.

The sympathetic release of norepinephrine during moderate-level exercise breaks down fat within adipose tissue, according to WebMD. Adipose cells shrink or swell like sponges as they store and release fat in the form of triglycerides. Free fatty acids are mobilized into the blood, then gobbled up and utilized by exercising muscles to prolong the depletion of critical muscle carbohydrate stores (glycogen).

Once you run out of muscle glycogen, you are out of energy. For instance, runners of a 26.2-mile marathon have been known to crash into the dreaded “wall” at about mile 20, notes Ready.Set.Marathon.

Endurance-trained athletes will develop a greater efficiency within their enzyme-driven biochemical pathways to burn a higher percentage of fat during moderate-intensity exercise compared to someone in inferior physical shape. As a result, they can use their glycogen reserves more sparingly.

Prolonging the sometimes inevitable exhaustion of muscle glycogen is extremely important in endurance sports. Consequently, some endurance athletes use various carbohydrate-loading regimens in the days prior to competition, according to Healthline.

The parasympathetic nervous system ideally acts like a brake by promoting a “rest, digest and repose” response to calm the body down after a stressful situation has passed. Unfortunately, the parasympathetic system cannot always balance out sympathetic responses due to heavy stress. In fact, stress can contribute to eating disorders, which some researchers now think might be more neurobiological than social-cultural, according to the National Association of Anorexia Nervosa and Associated Disorders.

Coaches and sports medicine staff are continually on alert for visible signs and symptoms (non-visible indicators) related to endocrine abnormalities in extremely competitive athletes. These types of athletes have the potential to develop serious medical conditions related to stress or overtraining.

These signs and symptoms include:

• Heart rate
• Blood pressure
• Body temperature
• Weight gain/loss
• Information revealed by medical images (X-ray, MRI or ultrasound)
• Swelling
• Bleeding
• Open fractures
• Skin rash size and color
• Changes in coordination
• Internal fatigue and pain
• Itching
• Nausea
• Vision problems
• Lightheadedness
• Headache

Additional Effects of Stress

Stress can be debilitating. It can aggravate existing mental and physical health problems or create new health problems. Stress is an unavoidable part of human existence and no one is immune to it, but it is important to be able to recognize when elevated stress from any source begins to cause problems.

Unfortunately, many people are not enough in tune with their bodies to effectively notice the cumulative effects of stress until they reach critical, health-threatening levels. Stress in small doses helps essentially every organ system get stronger, provided the body can handle and utilize the stress to its benefit. For instance, the muscle stress produced by lifting weights results in supercompensation and increased strength and endurance.

However, ongoing stressors that cannot be effectively curtailed can wreak serious havoc throughout the entire body. When it’s ongoing and extreme, stress becomes a risk factor for numerous, chronic mental and physical disorders, such as:

• Anxiety
• Depression
• Accelerated aging
• Heart disease due to promoting the formation of artery-clogging deposits
• Brain changes causing dementia
• Dilation or constriction of key blood vessels and small airways in the lungs
• Stroke
• Insulin resistance
• Digestive issues such as irritable bowel syndrome (IBS)

What Are the Signs of Stress?

There are various indicators that someone is in a high state of stress. For instance, people who are stressed may demonstrate:

• Increased irritability – getting agitated or frustrated more easily and raising their voice

• Depression – a loss of interest in activities that were previously enjoyed, feeling worthless or hopeless, loneliness, mood swings, excessive crying, emotional numbness and slowed body movements

• Gastrointestinal distress and appetite changes – nausea, stomach cramps, diarrhea, constipation, indigestion and inappropriate craving of certain foods

• Body aches, muscle tension, headaches and dry mouth – these reactions are often accompanied by sweating, shaking hands, and a feeling of coldness in the feet and other body areas epinephrine and other hormones redirect the body’s blood flow

• Sleeping difficulties – the sufferer may not be able to sleep through an entire night and seems visibly exhausted

Strategies for Coping with Stress

According to the Mayo Clinic, the use of biofeedback and relaxation techniques can be used to  train the body not to overreact to stressors that are not life-threatening. For instance, the body can be trained to better cope with stressors such as traffic jams and relatively minor squabbles with family and friends. 

Other methods of coping with high stress are:

• Meditation and breathing exercises – For decades, psychologists have used various mindfulness meditation and breathing techniques as therapeutic interventions. Learning how to silence your mind and body may take time, but it is well worth the effort.

• Spending more time outside – Taking a break and getting outdoor in the fresh air does wonders. Being in Nature provides relief and healing from the busyness of life by allowing you to absorb the beauty of the environment.

• Seeing a mental health professional – Despite the stigma associated with receiving help for mental health issues, getting started on the road to a stress-resistant lifestyle is well worth the cost. Cognitive reframing is often taught in therapy to help shift your perspective by replacing negative, flawed thought patterns with more positive, realistic ones.

• Visiting a doctor – It’s important to not miss regular checkups with your personal physician. Getting regular heart evaluations using an electrocardiogram (ECG), blood chemistry profiles and blood pressure checks are important to document changes occurring over time.

• Attending stress management seminars – These seminars can help you learn ways to handle unexpected stressors. Specific seminars targeting uncertainty about the future, climate change, ongoing traumatic events such as motor vehicle accidents and chronic illnesses afflicting family members are now available in several venues.

• Getting social support – Spending time with others to mutually build each other up via positive social connections and support can greatly reduce stress and improve your health. A lack of social support contributes to the release of stress hormones and a reduction in your feeling of well-being. Establishing companionships with friends, acquaintances, coworkers and relatives provide life-enhancing social networks. According to the buffering theory of social support proposed by physician and epidemiologist John Cassel and psychiatrist Sidney Cobb, close relationships indirectly help sustain persons during times of chronic stress and crisis.

• Using progressive muscle relaxation (PRE) techniques – PRE techniques are cost-free and easy to learn; there are many online articles and YouTube videos available. Most of these techniques involve tensing and releasing your muscles while you inhale and exhale moving from top to bottom of your body and then vice versa.

• Performing grounding activities – As a supplement to meditation and breathing exercises, there is also a technique that uses the five senses (also called 5-4-3-2-1). For instance, identify five things that you can see, four things that you can touch, three things that you can hear, two things that you can smell and one thing that you can taste.

• Exercising – Physical activity in any form – from walking to yoga, tai chi, and qigong – does not need to be intense or extensive. Also, it can easily be modified for individual abilities.

• Addressing the root causes of stress and behavior modification – Facing and overcoming specific challenges in your life can be difficult, but the subsequent lifestyle changes have many physical and mental benefits. For instance, limiting the amount of time spent online doing unproductive things can be replaced by online activities that can teach you how to set appropriate boundaries in workplace and home relationships. Similarly, using the Alcoholics Anonymous philosophy of accepting that there are things you cannot control, changing the things you can control and having the wisdom to know the difference – is an excellent strategy. Many causes for stress can be changed over time using “baby steps” if they cannot be changed right away.

• Pursuing art and other hobbies – Creativity in various arts and hobbies can greatly assist in relieving stress relief. Listening to and making music, spending time with animals, gardening, reading, and trying something new are all ways to break up detrimental, stress-related routines.

• Journaling – Keeping a regular journal can help you to clarify on how you feel and enhance problem-solving skills. It’s also a healthy way to vent stress.

• Improving the quality and quantity of your sleep – Chronic stress is a strong contributor to obesity. For example, stress can cause people to eat more and increase their weight while also decreasing the amount of sleep and exercise they get. But exercising can aid with stress relief and burning off excess calories so that it becomes easier to get more sleep.

• Stopping smoking and avoiding secondhand smoke – Nicotine can trigger an epinephrine release, which raises blood pressure and inhibits lung function. As a result, your heart must work harder.

There are various online tools available for recognizing stress, such as Mental Health America’s Stress Screener. In addition, there are also resources to visit if you feel stressed, such as Mental Health America and the American Heart Association.

Everyone Reacts Differently to Stress

Everyone responds at least a little bit differently to stress and also to various stress management techniques.  Because of the toll that chronic stress and stress hormones take on mental and physical health, individuals suffering from excessive stress should experiment. Ideally, they should determine which strategies work best to help reverse their stress responses and bring their bodies back to a normal, natural hormonal balance.

About the Authors

Daniel G. Graetzer, Ph.D., received his B.S. from Colorado State University/Fort Collins, a M.A. from the University of North Carolina/Chapel Hill and a Ph.D. from the University of Utah/Salt Lake City. He has been a faculty member in the School of Health Sciences, Department of Sports and Health Sciences, since 2015. As a regular columnist in social media blogs, encyclopedias, and popular magazines, Dr. Graetzer greatly enjoys helping bridge communication gaps between recent breakthroughs in practical application of developing scientific theories and societal well-being.

Daniel J. Borowick, M.S., C.S.C.S., is a former DEA Special Agent and Physical Task Test Administrator, who has over 27 years of tactical experience in state and federal law enforcement. Currently, he is a Certified Strength and Conditioning Specialist (CSCS^®) with certification from the National Strength and Conditioning Association (NSCA^®) and a private contractor in serving the US Army’s 1st Armored Divisions H2F/(Health and Fitness) Program. His capstone project, “Program Design Based on Genetically-Determined Type I and Type II Fiber Typing In Order to Achieve Optimal Athletic Performance,” was written under the guidance of Professor Daniel Graetzer and is available online. Any inquiries concerning this article and a program design in order to achieve optimal physical performance and human movement in order to be a better tactical athlete can be directed to Daniel Borowick at Dmexfit@gmail.com. CSCS and NCSA are registered trademarks of the National Strength and Conditioning Association.