How Exercise Affects Mental Health — The Good and The Bad!

Ryan Steger
How Exercise Affects Mental Health Endurance Sports Depression Anxiety Addiction

This article is not medical advice, please consult with your doctor for all plans of care.


  • Exercise is as effective as an antidepressant
  • Exercise decreases pain during and after exercise 
  • Exercise decreases anxiety 
  • Exercise can be addictive
  • Allostatic load can measure the stress your body is under
  • A high level of training stress can lead to overtraining which is bad 


How Exercise Affects Mental Health Endurance Sports Depression Anxiety Addiction

One of my passions is how exercise affects mental health, and I wanted to write about some of the good exercise can do, and some of the bad exercise can do. Mental health is important, and I want to say it is ok not to be ok. Please ask for help when you need it. In the United States, please call 988 or 911 if you are experiencing a mental health crisis. 

Mental health can not only affect your mood, but also your physical body too and I’m going to go into that later. Mental health affects around 12% of people according to the CDC. Mental illness can take many forms and it is tough to know what it looks like on the outside, but mental illness is a change in behavior, emotion or thinking. 

Good to Know

How Exercise Affects Mental Health Endurance Sports Depression Anxiety Addiction

I want to set the stage for a field of study called exercise psychology.
Exercise psychology studies how exercise affects the brain, and how it can impact psychological disorders. 

I have a Bachelor of Science from the University of Wisconsin Madison in Kinesiology, which is how exercise affects the human body. A scientist at the University of Wisconsin Madison greatly furthered the field of exercise psychology. His name was Dr. William P. Morgan, and I have had the pleasure of learning from his students and some of their work is referenced below. 

Exercise psychology is different from sports psychology as well, as exercise psychology looks at how exercise can improve mental and physical health and studies biomarkers to do that. Sports psychology on the other hand is looking at how to improve performance in sports. 

Another important distinction to note up front is the difference between chronic and acute exercise. Chronic is long-term, and acute is one single bout.

The Good!

How Exercise Affects Mental Health Endurance Sports Depression Anxiety Addiction

How Exercise can Improve Mood

There are a few leading theories as to how and why exercise improves mood and helps mental health, with research ongoing. The theories include:  

Runner’s High 

A pet peeve of mine is when people say runner’s high (defined as a state of euphoria and well-being experienced after a long exercise) is due to the endorphins. The high isn’t due to endorphins!

Endorphins are opioid products that the body makes (similar family to morphine), and there is also a product that can block opioids called Narcan. It works by preventing endorphins from bonding with opiate receptors.

In a double-blind, randomized study, Narcan was given to individuals before exercise bouts. Subject reported similar anti-anxiety feelings after exercise as when Narcan was not given. The opioid-blockade did not interfere with the development of runner's high.

So that means that endorphins aren’t directly responsible for that feeling. They may factor into that feeling, but are not the sole cause of that feeling like most people think.

How Exercise Affects Mental Health Endurance Sports Depression Anxiety Addiction

Endocannabinoid Hypothesis 

There is some speculation in the academic community that it might be that the body makes its own CBD supply and that could cause an anxiety reduction.

The Time Out Hypothesis 

Additionally, there is a hypothesis, called the Time Out Theory, that the time that exercise offers away from your problems can also cause anxiety reduction. This appears to be especially true with activities that allow individuals to be outside, for example, hiking, trail running, or mountain biking. 

The Bad!

How Exercise Affects Mental Health Endurance Sports Depression Anxiety Addiction

Exercise can have some highly detrimental effects. The first thing I want to touch on is exercise addiction. Exercise addiction is what it sounds like — addiction to exercise. This addiction can be an extremely harmful pattern to get into, with endurance sports being the most addictive type of sport.

“Regular physical exercise is an activity with a major capacity to maintain and improve physical and mental health. Nonetheless, in the light of the results of research, excessive practicing may cause serious health problems, giving rise to the appearance of addictive behaviors,” a National Library of Medicine Literature Review noted. 

“Indeed, a recent piece of research undertaken by Martin et al. (2017) has highlighted the fact that people practicing endurance sports continue despite being injured and in addition have high scores on the Inventory of Addiction to Exercise," the review continued. 

We’ve all heard about how bad stress is for us, but I want to explore how exercise can impact stress. Stress is not just mental; it can be physical as well. Unfortunately, your body does not really care if stress is physical or mental. 

When you exercise, you are stressing your body. However, if your body can not handle the stress exercise is putting on your body, then that’s when exercise can be detrimental. Exercise is voluntary stress, meaning that you can choose how much stress you want to put on your body. Work, family, school and life aspects are all often uncontrollable stressors. 

Allostatic Load

How Exercise Affects Mental Health Endurance Sports Depression Anxiety Addiction

Allostatic load
measures the amount of stress on your body, and accounts for all voluntary and uncontrollable stressors. When your allostatic load goes over what your body can handle, this is not necessarily a bad thing. Short-term overloading is necessary to gain fitness.

However, when allostatic load goes over for an extended period of time, then you can enter something called overtraining state. I ended up overtraining, and there are many different effects it can have on the body and mind. One of the main effects is bone-crushing fatigue. 

The research differs in how to measure allostatic load, from up to 25 different lab values to a 50 question questionnaire. I recommend being honest with yourself and doing daily check-ins. If you don’t want to exercise, don’t! If you do, great! If you’re tired, maybe cut that hike short. 

There is a screening tool called the Profile of Mental States called POMS for short. The ideal POMS mental profile looks like an iceberg, with the scale being low on the tension, depression, fatigue, anger, and confusion; and the profile will be high in vigor. When allostatic load starts to climb, however, then the scale flips, with tension, depression, fatigue, anger and confusion all being high and vigor being low. 

Closing Thoughts

How Exercise Affects Mental Health Endurance Sports Depression Anxiety Addiction

Please don’t just use exercise as a treatment for depression, anxiety or any other mental illness. Exercise can help with these diseases, but should not be the primary treatment. Please consult a mental health professional to create a treatment plan, which may include therapy, medicines and also exercise. 

Exercise is amazing but can have extremely detrimental effects too. A nuanced understanding of how exercise affects our bodies and brains can help us incorporate it into our lives in balanced, beneficial ways! 

My name is Ryan Steger and I’ve worked in the bike industry for 8ish years, and I’ve rode pretty much every type of bike out there. I graduated with my degree in Kinesiology from UW Madison in 2020 and I’m looking forward to sharing my love of bikes and all things outdoors! I’m pursuing a nursing degree, which is my journey currently. 

Trail talk

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