Why Does Exercise Make You 'High'?

Exercise may be hard work, but it can also make you feel great. Along with obvious physiological benefits, physical activity also provides a swift and sustainable psychological boost. The long-term benefits of exercise are fairly well established, with active people less likely to experience mental health problems such as depression and anxiety. The short-term 'high' that accompanies exercise is a little more opaque, however, with the body's natural chemical messengers only just starting to be understood. 

Whether you like running in the park, visiting the gym, or playing sport with friends, physical activity influences how you feel, how you look, and how you function. If you've ever experienced euphoria while exercising, you are certainly not alone. The exercise high is similar to a drug experience, from the biological processes that influence it to the sensations produced and risk of addiction. While working out does not carry the same health risks as doing drugs, the intense high associated with exercise can be a great way to drive your fitness forward. 

What is Exercise Euphoria?

Sometimes called the 'runner's high', exercise euphoria is a strong feel-good sensation that some people experience during or immediately after exercise. Along with physical discomfort, stress, and pain, this lively yet relaxing 'buzz' is shared by many fitness enthusiasts. Some people even describe it as a spiritual experience, with time slowing down and people feeling more connected with the world around them.

More often than not, the exercise high is the result of cardiovascular or endurance exercise, including activities like running, cycling, and high-intensity interval training (HIIT). When the body is moving and the blood is pumping, your brain goes into overdrive. While strength routines can still make you feel great, they often lack the movement and body heat necessary to fire up your body's chemical factory.

It's worth noting, however, that the 'high' associated with exercise is entirely subjective and almost impossible to pin down. The intensity of the experience varies between people and workouts, from nothing at all to mild satisfaction and transcendent bliss. There also seems to be something mysterious about this feeling, which can arise and disappear unexpectedly in a way that seems decoupled from physical stimuli.

Why Does Exercise Make You High?

Physical exercise, and in particular aerobic exercise, is known to activate the body's stress response. However, people are known to feel calm and relaxed when they exercise. As it turns out, not all stress is created equal, with the reduction of certain hormones partly explaining the tranquillity that accompanies exercise. When you work out, adrenaline and cortisol levels are reduced in your body as neurological changes occur in your brain. 

When you perform exercises, you're also releasing a number of feel-good brain chemicals. Endorphins are a prominent neurotransmitter, and these chemical messengers help to relieve pain and stress in the body and mind. Along with endorphins, physical activity also stimulates the release of dopamine, norepinephrine, and serotonin, all of which help to regulate mood. Endocannabinoids also have a huge role to play, with these molecules known to cause feelings of relaxation and pleasure throughout the body.

Links to Opioids and Marijuana

The two major chemical compounds responsible for the exercise high are endorphins and endocannabinoids. These components share similarities with two of the world's most popular drugs: opiates and marijuana.

As the body's self-produced opioids, endorphins produce chemical changes interpreted as pleasure and joy. Just like many opiate medications, endorphins are a natural and highly effective pain reliever. Endorphins are well-studied, with the runner's high long attributed to natural endorphin release in the body.

Endocannabinoids are naturally occurring molecules involved with lipid signalling. These compounds are known to mediate physiological functions and promote neurological balance. Just like marijuana, endocannabinoids are a natural substance that can help to reduce anxiety and manage pain.

As you can see, there are many similarities between healthy exercise and unhealthy drug use. These somewhat surprising connections could have powerful implications for drug treatment programs in the future. If healthy exercise provides the same rewards as unhealthy drug use, controlled exercise programs could act as a powerful substitute with positive behavioural consequences.

The Case for Endocannabinoids

According to a recent study, endocannabinoids may be more responsible for the runner's high than endorphins are. Cardiovascular stress mobilises endogenous cannabinoids, with their release possibly contributing to the analgesic and mood-elevating effects of exercise. While endorphin release is very real, it may be more likely to impact motivation levels before exercise than impact feel-good sensations after a workout.

New research by the University of Heidelberg studied mice before, during, and after running activity. While the mice were found to have both elevated endorphins and endocannabinoids, the mice remained happy and chilled out when opiate receptors were blocked. This did not happen when endocannabinoid receptors were blocked, with the mice just as anxious and still sensitive to pain.

According to separate research from the University of Missouri, endorphins play an important role when it comes to energy levels. Natural endorphin release has a significant effect on motivation, with the rats in this study drastically reducing their activity when their opiate receptors were blocked. Additionally, there are some indications that endocannabinoids actually cause the release of endorphins in the hypothalamus.

According to a review on the neurological effects of aerobic exercise, a single session of cardio at 70 to 80% maximum heart rate capacity provides the optimal increase of endocannabinoids. In order to reach this conclusion, the study analysed healthy men running at varying degrees of intensity (50%, 70%, 80%, and 90% of capacity) in a randomised order.

Exercise and Addiction

Along with a 'high' feeling, exercise and drugs also share the potential for addiction. While being addicted to exercise may not seem as bad as being hooked on drugs, the underlying psychological processes of addiction are actually quite similar. Exercise addiction involves an unhealthy obsession with physical fitness, and extreme cases are linked to physical harm and related mental health conditions such as depression and eating disorders.

Feeling buzzed after exercise is actually one of the symptoms of exercise addiction. Other symptoms include feelings of withdrawal when you don't exercise, managing your life around exercise, and being unable to stick to a reduced exercise regime. Even if you're not hooked, exercise euphoria can cause issues with injury if you push your body too far. While all of these things can be managed, self-awareness during and after exercise is the key to any healthy exercise program. 

How to Enhance Your High

Whether you want to enhance your euphoria or experience the runner's high for the first time, the best way to have fun is to stick to a regular fitness program. Whether it's joining a gym, buying some running shoes, or going for a long walk in your neighbourhood, there are lots of options available. As mentioned, intensive cardiovascular exercise is the best way to get your heart pumping and your neurons firing.

While you're unlikely to feel blissful every time you go for a run, fit and healthy people are less likely to be distracted by physical discomfort and more likely to enjoy natural endorphin and endocannabinoid releases. If you want to enhance your workouts, the best advice is to develop a more holistic approach to fitness. From the quality of the food you eat to the lifestyle choices you make, everything plays a role. While the exercise high is available to everyone, people who put the work in are much more likely to feel the rewards.