With an understanding of how the autonomic nervous system and hormonal systems are affected by stress it is easy to see why and how this happens.
When your body is under more stress than it can cope with for a long enough period of time, Adrenal Fatigue will ensue.
1. What is adrenal fatigue?
Adrenal fatigue is a condition where the amount of stress hormone ‘cortisol’ released from the adrenal glands is abnormal due to chronic stress. It is perfectly normal for cortisol to be released by the adrenal glands in response to stress. However, it is prolonged stress that becomes a problem.
What happens in a stressful (or fight or flight) situation is that the sympathetic nervous system is stimulated. Initially, adrenaline and noradrenaline are released to create an immediate response and cortisol is released slightly later if the danger (or stress) continues.
Now, the fight or flight response is required to mobilize the body in times of danger. Many years ago, it would have been due to predators or enemies or even whilst hunting.
What happens physiologically is that the blood vessels supplying the internal organs and neo-cortex of the brain constrict and the blood vessels supplying the muscles of the limbs and the reptilian brain dilate.
This causes the blood flow to be directed away from the internal organs and therefore away from the systems of digestion, detoxification, elimination and the immune systems so that it can support every system of the body required to survive the immediate threat. Instead the blood flow is re-directed to the limbs to enable the body to move quickly and to the reptilian brain to allow fast instinctive thinking.
If you were living thousands of years ago and you were lucky enough to survive a fight or flight situation, your body would slowly return back to a normal state. During this normal state, the parasympathetic nervous system becomes dominant. Breathing goes back to normal, heart rate reduces back down and the blood supply is redirected back to the internal organs and neo-cortex.
The reason this is important is that the internal organs are required to rebuild and regenerate tissues in the body and to keep a healthy immune system. Also, the neo cortex of the brain is required for logical thinking, planning and problem solving, which is required if you wish to plan your workouts, meals and sleep times around your busy lifestyle. If you’re stressed, it is much harder to make the right choices.
Stay tuned for Part 2, when I will explain more about Adrenal Fatigue and how it is linked to being Stressed, Tired and Overweight…