by Matt Weik
We often associate exercise with the feeling of not only exhaustion by the time you are done, but also a euphoric feeling that comes from the release of endorphins. Many people exercise for that simple reason—when the endorphins in the brain change the outlook of your day or something going on in your life. It’s a great way to deal with many of the stressors we face on a daily basis.
However, the number of endorphins released comes into play by the intensity of the exercise conducted by the individual. For example, the number of endorphins released from a slow walk will be grossly lower than the number of endorphins released by someone engaging in a HIIT style of training—and science has proven it.
Exercise adherence can be influenced by endorphin release
Not everyone exercises to look good. Sure, that might be one of the reasons or rather outcomes from exercise and living a healthy lifestyle, but it might not be the sole reason. For some, it’s the feeling they get during and after a workout.
We’ve all heard of marathon runners who during their workout, they get hit with the endorphin release and it helps them push on and increase their total mileage. All of a sudden, they are put “in the zone” and it’s as if they don’t feel anything—they just push on and watch the scenery around them change without any sensation coming from their body. They don’t feel the pounding and beating they are taking with each stride on the concrete. They don’t feel the fatigue in their legs or the deep breaths they are taking to provide their muscles with an adequate amount of oxygen. They find themselves in their own little world.
Recent research has looked at the use of HIIT (high intensity interval training) as it relates to endorphin release in the brain. HIIT training, for those who aren’t aware, is where you have intervals of high intensity workloads followed by a recovery phase. For instance, you might utilize HIIT when running. You could run or sprint for 30 seconds which can then be followed up by walking or jogging as a recovery phase for 60 seconds.
Researchers are finding that the release of endorphins from the activity actually mitigates the negative feelings associated with exercising at such a high intensity. In fact, many mentioned they felt great engaging in HIIT—giving them an almost euphoric feeling, similar to the example mentioned above with the marathon runners.
When the researchers compared HIIT to a 60-minute LISS (low intensity steady state) aerobic workout, they found the release of endorphins in the brain to be nowhere close to where it was when utilizing HIIT.
HIIT has been found to increase the release of opioid peptides as well which help manage the feeling of pain as well as enhance and improve an individual’s emotions.
To view this, researchers used positron emission tomography (PET) testing. Each of the participants in the study agreed to be injected with a compound that seeks out and attaches to opioid receptors in the brain. These compounds are radioactive which allows the use of the positron emission tomography technology to view the differences in training methods as they relate to the release of opioid peptides.
One researcher mentioned, “Our results highlight that exercise intensity affects endorphin release and that the brain opioid system is involved in both positive and negative feelings caused by physical exercise performed at different intensities. Exercise-induced endorphin release may be an important mechanism which supports exercise motivation and maintenance of regular exercise. At moderate training intensities, the pleasurable sensations caused by the possible release of endorphins may promote habitual exercise. At very high exercise intensities the release of endorphins appears to be linked to increased negative feelings and pain, and may be needed to manage the emotionally and physically demanding challenge. However, such negative feelings may discourage further exercise. Exercise intensity should be taken into account when starting new exercise routines.”
So, what’s the takeaway? If you want to increase the number of endorphins and opioid peptides released in the brain to feel better and attain a euphoric feeling during as well as after your workouts, you’re going to want to engage in some type of high-intensity exercise. While a lower intensity will release some endorphins, it unfortunately isn’t on the same level as utilizing the HIIT method.
1.) Saanijoki, Tiina., et al. “Opioid Release after High-Intensity Interval Training in Healthy Human Subjects.” Neuropsychopharmacology, 2017.