- Endorphins cannot be responsible for the mood-enhancing effects of exercise because they can’t pass through the blood-brain barrier
- The complex, endogenous, endocannabinoid system appears to be the most likely cause of the feel-good effects of prolonged, rhythmic forms of exercise like running or cycling
- These effects are profound and can help to manage anxiety, depression, improve cognition and memory – and, usefully, they can become mildly addictive because they play on the brain’s central reward system
- This reward system is very closely related to the opioid system involved with sugar addiction, and may be one reason why beverage makers try to exploit the association between sugary drinks and activity
- Most of us may be better off recognising the link, hold back on sugars in our diets, during, before and after we exercise, and learn instead to become more reliant on fat-burning through the process of keto-adaptation
Most of you will have either heard of, or experienced, the ‘runner’s high’. It’s that mildly euphoric state that calms at the same time that some runner’s feel after a steady, longish, but usually non-competitive run. Cyclists experience it too, although the term, ‘cyclist’s high’, doesn’t roll off the tongue in the same way. It’s all about the release of endorphins, right? Well, that’s how the Merriam-Webster dictionary defines it. Wrong.
Exercise and endorphins
It was back in the 1980s when sports scientists discovered that prolonged exercise would lead to an increased production of endorphins, opiate-like peptides that mimic the effects of morphine. They were right about the analgesic effects from these endogenous opioids produced as a result of repetitive contraction of skeletal muscles as found in prolonged rhythmic exercise. Over the years, the idea stuck. And sticky ideas are hard to shift, even if they are wrong.
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