Understanding the physiology of stress and using exercise to combat it
|Montreal Gazette 20 Apr 2017 at 06:10|
Stress is a normal part of life and, in fact, we need a certain amount of stress to feel energized, excited and joyful. However, it is when we are struck with high levels of uncontrollable stress that the body breaks down. Understanding the physiology of stress and ways to mitigate stress can help you to understand how best to manage it in your life.
The stress response in the body is like setting off an alarm that activates a cascade of physiological reactions to prepare the body to combat perceived or real danger. This primitive survival mechanism is known as the “fight or flight’ response. When the brain detects stress, a carefully orchestrated and instantaneous sequence of hormonal changes and physiological responses occur. In fact, every physiological system of the body is affected.
When the brain detects stress, it secretes a substance called corticotropin-releasing hormone from the hypothalamus, a part of the brain that acts like a control centre. This signal tells the pituitary gland to release adrenocorticotropic hormone that then alerts the adrenal gland to release the stress hormones; cortisol, noradrenaline and adrenaline, which activates the sympathetic nervous system.
The autonomic nervous system has two components, the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system functions like the gas pedal in a car. When you step on it, it pushes you into high gears and triggers a burst of energy. The parasympathetic nervous system acts like a brake. It promotes calming after danger has passed.
Stress hormones cause heart rate, breathing and blood pressure to rise. Increasing blood flow to supply the brain and muscular system with more oxygen and energy to produce greater strength and power to battle the stressor. Sight, hearing and other senses are heightened. Meanwhile, hormones and changes in blood flow and circulation to the brain and major muscles redirects blood supply away from the digestive and reproductive system, causing them to slow down. The liver is pushed to release higher levels of glucose (sugar) into the blood steam to produce more for energy.
Muscles contract and hold tension until they are physically used to run or fight. It is commonly felt in the neck, jaw and back causing headaches, low back pain and other symptoms. This tension remains until the energy is used or the parasympathetic nervous system come into play to calm you down.
These changes happen so quickly that we are not consciously aware this is taking effect. In the normal stress cycle, once danger has passed the body self-regulates and dampen the stress response via the activation of the PNS bringing all systems back to homeostasis or balance.
Long term stress creates an imbalance in normal hormone levels and will begin to break down the systems in your body. Unresolved stress can affect the immune system leading to illness as well as, high blood pressure, cardiac irregularities, diabetes and weight gain. Think of it in the same way as physical training. If you push your workouts hard every day the body doesn’t have the opportunity to repair leading to overuse injuries, adrenal fatigue and decreased performance. The same is true for constant chronic levels of stress.
Interestingly, when you exercise you stimulate the sympathetic nervous system to give you the strength to do the activity. The difference with exercise versus perceived chronic stress is the body uses all the resources to produce energy for work, training the body to effectively regulate stress. When an exercise bout is complete the body immediately resets the systems via the PNS to come back to a state of calm. Biologically, exercise seems to give the body a chance to practise dealing with stress and improves the bodies communication centers to deal with it.
It is a well-known fact that physical activity is a positive way to manage stress. The physiological benefits of training the body builds a stronger foundation to handle stress. Finding the appropriate amount of exercise and managing exercise intensity with recovery is critical for long term health and stress management. Moderate to hard exercise improves cardiovascular health, enhances immunity and builds resiliency to stress. Continuous intense exercise without the appropriate amount of recovery will lead to overtraining and chronic levels of stress hormones. When this happens, exercise amplifies rather than protects against the health risk of stress. It is important when you complete an intense workout that you take the time to recover the body by physically cooling down, stretching, refuelling appropriately, practising deep breathing and rest.
Stress management is not a one-size-fits-all. Everyone is a unique position based on current life stresses, health, activity level and stress management practices. Depending on where you are and what you prefer, differenttechniqueswill effectively combat stress. Experiment with these different techniques and see what works best for you: