In what might be described as something of a chicken-or-egg scenario, scientists discovered the receptors for endorphins before they identified the neuropeptides which we call endorphins. Endorphins, (short for endogenous morphine) are naturally-occurring opioids which are released from your pituitary gland. You may already know that endorphins are released during physical activity and that they help promote feelings of well-being. Beyond this the release of endorphins has been shown to decrease anxiety, increase self-esteem, and reduce appetite.
What you may not know is that endorphins play another important role in pain control, hindering or inhibiting signals of pain. Endorphins have actually been cited as a stronger source of pain relief than morphine. So how do they work?
First, remember that pain is just a negative perception of certain stimuli. It is a critical evolutionary tactic to make you jump (sometimes quite literally) away from dangerous situations. For instance, stepping on a nail is painful and you will quickly lift your foot. Though some damage may have been done, it is far less than if you had stayed standing on the nail, which would damage nerve endings, muscles, and lead to infection.
Your body interprets pain through a series of signals from your nervous system as it responds to particular stimuli. When you encounter such stimuli, say by stepping on a nail, your body releases a large amount of something called Substance P, which is a major pain neurotransmitter. Substance P then causes increased sensitivity to the stimuli, which snowballs into you experiencing more and more pain.
Where do endorphins tie in? Well, while you’re wasting time standing on a nail, your body is setting off another chemical chain reaction to come to the rescue. Upon experiencing pain, your hypothalamus releases endorphins, which in turn bind to opioid receptors in the Peripheral Nervous System. This binding inhibits the release of Substance P. As already indicated, the inhibition of Substance P decreases the overall perception of pain. The subsequent decrease in pain signals effectively “turns off” the chain reaction above, slowing the release of endorphins.
Endorphins also bind to opioid receptors in the Central Nervous System. This binding inhibits the release of gamma-aminobutyric acid (GABA) which results in an increase in the production of dopamine. Dopamine is a pleasure neurotransmitter, one often associated with corticotropin-releasing hormone (CRH) which tells your pituitary gland to produce pro-opiomelanocortin (POMC). POMC is then broken down into endorphins.
Endorphins, like so many proteins in your body, are diversely talented peptides, influencing a huge range of your experiences, including pain, anxiety, and happiness. They reward behaviours such as winning a hand of cards or falling in love.
Moving back to rowing – as this author always tends to – it therefore makes sense that endorphins play a larger role in rowing than you may think. While we know that physical activity can cause the release of endorphins which work to stimulate feelings of happiness and decrease the perception of pain, the rowing world offers another aspect to the equation: behavioural synchrony.
Behavioural synchrony, the coordinated performance of a collective action or series of actions by a group, is observed in dance, musical concert, and sports like rowing. A crew must move flawlessly, seamlessly in rhythm. More so, they must do this at the absolute peak of their physical ability. This makes rowers the perfect petri dish in which to observe the effect of enhanced endorphin release. They are producing massive power output and doing so in perfectly precise synchrony.
A group of researchers at the University of Oxford knew just that when they conducted a study into the impact of endorphin release on a team of Oxford male rowers. They wanted to determine whether the additional demand of behavioural synchrony, on top of intense physical activity, would increase the effect of endorphins.
It’s difficult to measure endorphin levels directly, as this requires an invasive lumbar puncture which most people aren’t lining up to volunteer for. Instead, it is common practice to measure endorphin levels by assessing pain tolerance. Why? Because, as we discussed earlier, the release of endorphins hinders the perception of pain. Someone producing copious amounts of endorphins, say after rowing 6x500m, will have a dulled pain response and therefore a higher tolerance.
Scientists compared the pain tolerance of twelve male rowers before and after rowing 45 minutes continuously. They did so separately on individual ergs in isolation, and also as a group, with rowers instructed to stroke in time on their ergs in the same room. The results? Rowing together, as a crew, significantly increased the pain tolerance observed in the athletes. This can be taken to mean that when rowing in sync, individuals produced higher levels of endorphins.
When considering the many beneficial benefits of endorphins, such as reducing anxiety, increasing pain tolerance, and promoting feelings of happiness, these results are certainly positive for rowers. The Bobby McFerrin 1988 hit song crones “Don’t worry, be happy”. I say, “Don’t worry, keep rowing.”