Within the online running community, we all see the term ‘runners high’ regularly used and often hear of the unbeatable feeling of elation experienced as a result of exercise. And in my view, it's true. Personally, not many things make me feel as much of a positive uplift than an enjoyable run in the the sunshine, a sweaty HIIT session or a relaxing yoga flow. Moving your body really does serve as a natural mood booster, comparable only to my first sip of warm coffee in the morning.
Whilst reading Bill Bryson's bestseller, The Body, I've found myself constantly intrigued and astounded at the intricate complexities of the human body. Studying Psychology at University, I have some in-depth knowledge around particular elements of our human psyche and biological mechanisms. However, never have I learnt such a great amount about how our body actually works at a granular level. His brief discussion on the tiny neurochemicals released by our body, called endorphins, sparked my interest into exploring their pivotal role in more detail and depth.
What Are Endorphins?
In essence, endorphins, a type of endogenous opioids, are peptides released by the pituitary gland to cause feelings of intense pleasure or help relieve pain, resulting in their common nickname of the 'feel-good' chemicals. They achieve this through binding to opiate receptors, inhibiting the communication of pain signals. Due to the widespread nature of these receptors throughout our peripheral nervous system, spinal cord and brain, endorphins can have diverse effects within our body. One key role they possess is involvement in our brain's 'reward system', activated as a response to experiencing stress or pain, but also during activities like eating, drinking, sex and exercise.
The name 'endorphins' comes from a mixture of the word 'endogenous', meaning to originate within the body, and 'morphine', which is a well-known pain reliever. Combining the two, we have a naturally occurring pain relief. From an evolutionary perspective, endorphins offer us a great survival advantage. As humans, we endeavour to partake in activities that maximise pleasure and minimise discomfort, which is something endorphins help us to achieve by allowing us to continue regardless of injury or stress.
Endorphins & Exercise
As mentioned, endorphin release is strongly associated with intense physical exercise, often resulting in the euphoric feelings us runners experience after a tough or prolonged session. This feeling of euphoria is a consequence of our body falling into a relaxed psychological state. Within research this has been supported, with correlations being found between vigorous exercise and heightened levels of endorphins within our blood plasma. Notably, some research has suggested that the type of exercise plays a role in this endorphin release - although evidence has been found to support the strong association in both anaerobic and aerobic forms of exercise.
Additionally, due to endorphins being our bodies primary natural pain reliever, they often inhibit us from feeling any pain or discomfort within our muscles during prolonged exercise. Dependent on the situation, this can be viewed as a blessing or a curse. Undoubtedly, running through any form of injury is not advised and should be avoided, therefore meaning being blissfully unaware could actually cause us more harm than good. On the other hand, the muscle soreness we experience due to a particularly exhausting activity is happily blocked from our minds.
However, whilst conducting my own desk research to produce this post, I continually read scientific articles and journals that stated that no definitive conclusion could be drawn to simply deduce that these euphoric feelings post-exercise are a result of endorphin release. Upon first discovery, this quite honestly shocked me. Although the link has been branded 'extremely likely' by many, I did not anticipate this to be a highly contended and inconsistent area of research. Frequently on social media and other platforms, people brand endorphins to be the somewhat 'king of exercise'. Yet, even the science has not made such bold claims.
One study conducted within the past 12 months even ruled out endorphins altogether in causing this 'runner's high'. Their research suggested other rewarding molecules, eCBs, released during exercise are the culprits. Using an opioid blockade, they found participants still showed the two key elements of a 'runner's high', euphoria and reduced anxiety, concluding the opioid increase could therefore not be responsible.
Personally, I felt it important to highlight what I had learnt. As I said, endorphins are considered highly likely by most to be the cause of the elated feelings we experience as a result of exercise due to their inhibiting effect on our bodies stress response. But, it is important to remember that much of the science has resulted in a looming question mark upon the page rather than a conclusive answer.
The mood-boosting effects of exercise is no secret to any of us who regularly embed it into our routines. Social media frequently strives to remind us of the unequivocal benefits that moving your body can have on your mental wellbeing. But, this isn't just "fitness influencers" out to make money. Many studies have found indications of exercise reducing negative, emotional feelings, suggesting that endorphins may play a significant role in helping to alleviate symptoms of depression or severe anxiety. Having said that, much as before, more conclusive research needs to be conducted in this area to draw concrete results.
Reading this, you may begin to wonder the difference between dopamine and endorphins as I did myself. My understanding of dopamine's role in the body was as a chemical messenger that aids us in feeling happiness and pleasure. Although appearing to have similar effects, the key difference is that endorphins help to reduce stress and pain, which quite obviously in turn would result in an increase in our happiness. Dopamine, however, is greatly responsible for us feeling pleasure and motivation via our body movements, meaning it is not considered a natural pain relief like endorphins. Higher levels of endorphins likely results in higher levels of dopamine, explaining why both are often described as our "happy chemicals". Deficiency in both of these neurotransmitters has been linked to individual's experiencing depression, demonstrating the important impact they have upon our mental wellbeing.
I hope this short discussion piece offers a slither of insight into the role of endorphins in our body and how they may, or may not, be impacted by exercise. All of this information was gathered by my own desk research, reading as many credible articles as I could source online, which are all linked in-text. Our bodies are an extremely complex, multi-functional system, meaning the information I have provided here as barely scratched the surface. But it is an intricate system that I wish to delve further into and expand my knowledge on, given without it we would all cease to exist.
Let me know in the comments below if you found this to be an interesting read and please share any extra knowledge you may have on the topic that I haven't touched upon!