Physical Activity and Depression
If you’re like me, you enjoy learning about the benefits of an active lifestyle. If so, I hope you’ll be as pleasantly surprised as I was to discover the value of physical activity to your mental health.
It has been shown that those who live sedentary lifestyles experience much higher rates of depression [1]. Did you know that 85 minutes a week of leisurely physical activity reduces risk of depression by up to 45% [1]? This reduction can be furthered by increasing your activity levels to around 150 minutes per week of moderate to vigorous physical activity, and tends to reduce continually as activity levels increase. The cause of this seems to come from many factors and contributors. One of these is the increase in central norepinephrine neurotransmission. Norepinephrine is a messenger chemical in the brain which is utilized for a slough of different functions, some of which being: attentiveness, emotional regulation, melatonin production for sleep, and blood glucose management. The increase in norepinephrine can also help people with bipolar disorder, as one of the symptoms is lowered levels of norepinephrine in the brain [8]. This relationship between norepinephrine transmission and our body can be seen in the infographic below.
For those who already suffer from depression related disorders, the benefits of physical activity are still drastic. These benefits include an increased perceived self-efficacy (the belief in yourself to achieve goals) and sense of mastery all which lead to improved self confidence and positivity; this generally goes hand in hand with improving depression [5]. An increase in negativity is generally partnered with increase in depressive states, so logically it makes sense that increasing positivity should reduce the frequency and duration of these states. Other positive effects can be the distraction from day to day stressors, and an improved opinion of oneself that stems from a sense of accomplishment.
Of course, the value of increased serotonin synthesis and metabolism in the brain can not be left out. When a person is affected by depression-related disorders, they typically experience a drop in serotonin levels. This drop can negatively affect everything from appetite and digestion to sleep and sexual desire/function. Physical activity increases serotonin levels partially due to the fact that, as a person exerts themselves, the increased motor function raises the rate at which serotonin is “fired” in the brain [7]. Another contributing factor in serotonin production is that as a person’s exercise levels increase, the level of tryptophan (an amino acid used to synthesize serotonin) increases as well. The most effective forms of physical activity for increasing serotonin in the brain are assorted aerobic activities such as hiking, running, biking and swimming.
It may seem overwhelming to make these changes; however, when starting out, it only takes exercising a small amount to make a difference. The Anxiety and Depression Association of America (ADAA) states that there are notable differences in stress levels and demeanor after as little as 5 minutes of consecutive aerobic activity (such as walking, cycling and jogging). After you master the 5 minute of aerobic activity mark you can try adding time slowly until you are at 20-30 minutes of activity 3-4 times a week and before you know it you might be at 7 sessions per week. Serotonin has been shown to be ideally regulated with 7 sessions per week of at least 30 minutes in length so this can be a good long term goal for all of us to work toward once ready. Remember, your physical activity does not have to be fancy in order for you to receive benefits. Benefiting your mental health through physical activity can be as simple as walking 5 minutes more a day. Happy exercising!
References:
Physical Activity and Depression in Young Adults https://www.ncbi.nlm.nih.gov/pubmed/19062235
Physical Activity, Exercise, Depression, and Anxiety Disorders http://spers.ca/wp-content/uploads/2013/08/physical-activity-and-exercise-on-anxiety-and-depression.pdf
Synapses and Neurotransmitters http://thebrain.mcgill.ca/flash/i/i_01/i_01_m/i_01_m_ana/i_01_m_ana.html
How The Brain Knows When The Body ‘Hits The Wall’ https://www.livescience.com/1669-brain-body-hits-wall.html
8 Suggestions for Strengthening Self-Esteem When You Have Depression https://psychcentral.com/blog/8-suggestions-for-strengthening-self-esteem-when-you-have-depression/
Physical Activity Reduces Stress https://adaa.org/understanding-anxiety/related-illnesses/other-related-conditions/stress/physical-activity-reduces-st
The Effects of Exercise on Serotonin Levels https://www.livestrong.com/article/22590-effects-exercise-serotonin-levels/
What Chemicals Are Involved With Bipolar Disorder? https://www.livestrong.com/article/234421-what-chemicals-are-involved-with-bipolar-disorder/