The Stress-Exercise Connection—how does this work? Part 2

Continued from part 1.

Life-insuranceThere are three regions of the brain that control the stress response: The Amygdala, which detects, treats and triggers the fight-or-flight response; the Prefrontal Cortex, which helps us deal calmly with stress, and can shut down the fight-or-flight response; and the hippocampus, which supports our stress recovery. Neroscientists now know that chronic stress can change these brain regions in a way that makes us more sensitive and less resilient to stress. When we have stress all the time, these areas weaken and the brain gets worse at managing stress. When this goes on for a prolonged period of time, these changes in the brain can lead to depression, cardiovascular disease and accelerated aging. But as we mentioned at the beginning of this article, exercise can be a way to manage or even cure stress. Let’s see how that works.

Numerous studies in 2011 and 2012 have shown that exercise has shown tremendous promise as a neuroprotective intervention. Exercise protects our brains from stress in several ways. When we exercise (and the more intense we can exercise the better the result) we increase something called Brain-Dirived Neurotphic Factor (BDNF), which maintains brain health. Not only does exercise give us more BDNF, it also triggers the brain’s self-repair processes. And last, exercise also activates the brain’s self calming system by releasing a neurotransmitter called GABA ((gamma-Aminobutyric acid) in order to restore balance in the autonomic nervous system. Perhaps the most encouraging research is that for someone who makes exercise a part of his or her life, exercise can create a STRESS RESISTANT BRAIN! (Fleshner et. al. 2011).

The question is how much does one need to exercise and at what intensity? As previously stated, intense exercise is good, but intense exercise for a prolonged period of time is not good for our cardiovascular system, our immune system or our brains. So it seems that moderate exercise for less than an hour at a time brings the best results. Overtraining, meaning intense exercise for a prolonged period of time can have the opposite effect of what we are trying to achieve. An over-trained athlete can actually develop exaggerated stress response and fail to recover between his workouts. That results in elevated stress hormones, and instead of exercise giving us long-term protection against stress, it amplifies our stress.

Remember that exercise in all of its forms, aerobic and resistance training does help us manufacture more of the feel-good neurotransmitters in our brains, serotonin, dopamine and norepinephrine. These are the same hormones that anti depressant medications work on. The now famous SMILE (Standard Medical Intervention and Long-term Exercise) study at Duke University in 1999 the researchers followed 156 patients between the ages of 50 and 77 who had been diagnosed with major depressive disorder (MDD). They were randomly assigned to one of three groups: exercise, medication or a combination of medication and exercise.

The exercise group spent 30 minutes either riding a stationary bicycle or walking or jogging three times a week. The anti-depressant used by the medication group was sertraline (trade name Zoloft), which is a member of a class of commonly used anti-depressants known as selective serotonin re-uptake inhibitors. To the surprise of the researchers, after 16 weeks, all three groups showed statistically significant and identical improvement in standard measurements of depression, implying that exercise is just as effective as medication in treating major depression and it doesn’t have the negative side effects of the various medications.

We are all familiar with the wonderful physiological advantages of exercising, helping to prevent heart disease, cancer, diabetes and a host of other diseases. But we now know that exercise can help us in our battle against all types of daily stress. Reducing stress through exercise will “add hours to your day, days to your year, and years to your life.”


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