The ‘runner’s high’ may result from molecules called cannabinoids — the body’s own version of THC and CBD

The “runner’s high” has long been attributed to endorphins. These are chemicals produced naturally in the body of humans and other animals after exercise and in response to pain or stress.Photo by Getty Images

Many people have experienced reductions in stress, pain and anxiety and sometimes even euphoria after exercise. What’s behind this so-called “runner’s high”? New research on the neuroscience of exercise may surprise you.

This research has implications for everyone who exercises with the aim of reducing stress and should serve as a motivator for those who don’t regularly exercise.

Health benefits of exercise

The surprising role of endocannabinoids

But many people do not realize that humans also create their own versions of these chemicals, called endocannabinoids. These are tiny molecules made of lipids – or fats – that circulate in the brain and body; “endo” refers to those produced in the body rather than from a plant or in a lab.

Understanding the runner’s high

Interestingly, we observed this exercise-related boost in endocannabinoids across different types of exercise, including running, swimming and weightlifting, and across individuals with and without preexisting health conditions. Although only a few studies looked at intensity and duration of exercise, it appears that moderate levels of exercise intensity – such as cycling or running – are more effective than lower-intensity exercise – like walking at slow speeds or low incline – when it comes to raising endocannabinoid levels. This suggests that it is important to keep your heart rate elevated – that is, between about 70% and 80% of age-adjusted maximum heart rate – for at least 30 minutes to reap the full benefits.

There are still a lot of questions about the links between endocannabinoids and beneficial effects from exercise. For example, we didn’t see consistent effects for how a chronic exercise regimen, such as a six-week cycling program, might affect resting endocannabinoid levels. Likewise, it isn’t yet clear what the minimum amount of exercise is to get a boost in endocannabinoids, and how long these compounds remain elevated after acute exercise.

Despite these open questions, these findings bring researchers one step closer to understanding how exercise benefits brain and body. And they offer an important motivator for making time for exercise during the rush of the holidays.

• thegrowthop@postmedia.com