Why Does Exercise Impact Mood?

Happy person– good mood! May5th 2020

Feeling Good from the Inside-Out

Are you feeling sad or down? Exercise might help your mood!

Exercise can positively impact your health in a myriad of ways, with the most well-known benefits including improvements in strength, stability, and endurance that are developed from the physical aspect of exercise. However, less is known about the mental benefits of participating in exercise on mood, such as the reduction of stress and even depression and anxiety, as some evidence suggests. People often say that participating in physical activity ‘releases endorphins’ to explain why we feel so good after we finish running a mile or completing a set of squats, but what does that really mean and how does exercise lead to these long term benefits in mood?  

Disclaimer: if you have a mental health disorder or concern about a mental health disorder please consult a mental health practitioner before engaging in a new exercise program.

The neuroscience of exercise & mood 

When we exercise, we are deliberately inducing a state of stress in our bodies. In response, the human body releases neurochemicals and neurotransmitters to continue to function optimally. The neurochemicals are endorphins, and they help our body perceive less pain and discomfort during strenuous exercise as they bind to the opioid receptors in our brain, which has a very similar effect to morphine on the body. Neurotransmitters such as norepinephrine, dopamine, and serotonin are engaged in the ‘fight or flight’ response that we are creating by exercising. Norepinephrine increases heart rate and activates the release of glucose to be broken down for energy, dopamine combats norepinephrine by dilating the blood vessels to increase blood flow, and serotonin regulates many processes in the body, including your emotional response. 

Our mood is the result of a combination of many hormones being released and absorbed in the body in response to our environment. For example, happiness is created by a long list of hormones, but those that are most commonly recognized are serotonin, dopamine, oxytocin, and beta-endorphin. Lucky for us, some of those same substances are released during exercises, like serotonin and dopamine, As stated above, these are also known as happiness hormones. To elaborate, dopamine taps into our ‘motivational salience’ cognitive process, which regulates the intensity of our behavior to either achieve or avoid a goal. Serotonin can override the original impulse brought about by dopamine, and is the source of consistent motivation. As it turns out, endorphins allow us to push through the pain during exercise by essentially numbing the body, but we have neurotransmitters like dopamine to thank for the feel-good euphoria of ‘runner’s high’, as well as serotonin for the increased motivation that we experience during and after a session of physical activity. 

To prove the link between exercise and mood, a collective study investigated the results of 20 peer-reviewed animal and human studies spanning the course of over 20 years that were researching both the levels of serotonin and dopamine post aerobic exercise, as well as the possibility of using exercise as a treatment for drug rehabilitation, as drug abuse significantly disrupts the network of dopaminergic and serotonergic systems in the body. The qualitative analysis found that in all of the studies, circulatory levels of dopamine and serotonin were increased after physical activity. In fact,

“exercise can be a useful tool in the prevention and treatment of drug dependence.”

(Davdand & Arazi, 2018)

There is a plethora of evidence outside of this study to suggest that exercise improves mood immediately after physical activity, but there are also benefits from exercise that can last far into the future. 

The long term benefits of exercise on the mind

Under stress, our body also releases a protein known as Brain-Derived Neurotrophic Factor (BDNF), which improves cognitive function by protecting and repairing our memory neurons. There are multiple studies that found increased levels of plasma BDNF after completing an extended aerobic exercise program, in addition to increased levels of BDNF being related to a quicker response rate to antidepressants (Phillips, 2017). BDNF is the reason why people feel a sense of clear-headedness after completing a session of exercise, and there is also evidence to suggest that increased levels of BDNF can lead to improved cognitive function and information processing as well (Chang et al., 2017). 

In addition to improving mood, there is also evidence to show that exercise can create a positive impact on mental resilience. In a study that surveyed 284 high school students, those that reported that they were more physically active scored higher on the Mental Toughness Questionnaire. The researchers defined mental toughness as

“individual’s natural or developed capacity to be consistently successful in coping with the stress and anxiety associated with competitive and stressful situations.”

 (Gerber et al, 2012).

When considering the big picture, this makes perfect sense. By purposefully inducing stress in the body in a controlled environment like during exercise, when stress arises again it seems to be much more manageable as we have experienced the exact same symptoms (increased heart rate, perspiration, and feelings of unsteadiness) previously through physical activity. This is also why there is evidence to suggest that general anxiety can also be reduced through exercise, as we gradually teach our body that the symptoms of stress can actually be a good thing. Researcher Dr. Otto Smits, Co-Director of the Anxiety Research and Treatment Program at Southern Methodist University in Dallas, states

“Exercise in many ways is like exposure treatment”

“People learn to associate the symptoms with safety instead of danger.”

(Weir, 2011)

Which type of exercise has the greatest ‘happiness potential’? 

A small study investigated the effects of aerobic, anaerobic, and resistance exercises on levels of serotonin and beta-endorphin, which are hormones associated with happiness. After eating the same breakfast and completing a short session of exercise from one of the aforementioned groups (no exercise in the control group), a blood sample was taken from the subjects and analyzed. Researchers found that all exercise groups showed improvements in the happiness hormones, but aerobic exercise created significant increases in serotonin and BDNF compared to the other exercise groups (Sharifi, Hamedinia, & Hosseini-Kakhak, 2018). 

As the study above had a small sample size of only 32 participants, it is difficult to generalize the results of aerobic exercise being the best form of exercise to release the ‘happiness hormones’ to all participants of exercise today. Unfortunately, most studies investigating the mental benefits of exercise only include aerobic exercise as their experimental group, and more research should be conducted to compare the mental health benefits and neurological effects of various forms of exercise.  

With that being said, the study above saw improvements in serotonin and beta-endorphin throughout all exercise groups, and this increase in neurotransmitters post exercise is consistent throughout other research as well. Any form of exercise has the potential to create that ‘runner’s high’, as long as you are engaging that fight-or-flight response by increasing your heart rate. Whether your go-to exercise is a brisk walk, a long bike ride, or hitting the weight room, physical activity can make you feel good from the inside-out. You just need to get moving!If you need help moving to feel good on the inside and the outside, contact us at 352-373-2116 or schedule an appointment below.

By Casey Jackson and the ReQuest team.

References 

Chang, Y., Alderman, B,L., Chu, C., Wang, C., Song, T., Chen, F. (2017, February 1). 

Acute exercise has a general facilitative effect on cognitive function: A combined ERP temporal dynamics and BDNF study. Psychophysiology, 54, 289-300. DOI: 10.1111/psyp.12784 

Dadvand, S.S., Arazi, H. (2018). The impact of exercise training in the treatment of drug 

addiction. The role of changes in neurotransmitters. Baltic Journal of Sport & Health Sciences, 111(4), 12-22.  

Gerber, M., Kalak, N., Lemola, S., Clough, P.J., Puhse, U., Elliot, C., Holsboer 

Trachsler, E., Brand, S. (2012, June). Adolescents’ exercise and physical activity are associated with mental toughness. Mental Health and Physical Activity, 5(1), 35-42. https://doi.org/10.1016/j.mhpa.2012.02.004 

Phillips, C. (2017, August 8). Brain-derived neurotrophic factor, depression and physical 

activity: Making the neuroplastic connection. Neural Plasticity, 2017, 1-17. https://doi.org/10.1155/2017/7260130

Sharifi, M., Hamedinia, M.R., Hosseini-Kakhak, S.A. (2018). The effect of an exhaustive 

aerobic, anaerobic, and resistance exercise on serotonin, beta-endorphin and BDNF in students. Physical Education of Students, 22(5), 272-277. Doi: 10.15561/20755279.2018.0507  

Weir, K. (2011, December). The exercise effect. Monitor on Psychology, 42(11), 48. 

Retrieved from: https://www.apa.org/monitor/2011/12/exercise  

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