Vennessa McConkey
Exercise Intolerance and Autoimmune Diseases
Updated: May 15, 2021

Although the food we put at the end of our fork is important to managing our health, you can’t ignore exercise — it is practically a magic bullet to feel and function better. Many studies show the multiple benefits of exercise. Not only does it keep our muscles and bones strong, exercise also triggers the release of chemicals that boost energy, dampen inflammation, and improve brain function.
BUT, what if exercise gives you brain fog, crashes your energy, takes forever to recover from, and flares up your thyroid or autoimmune symptoms? If you are one of the people working to manage autoimmunity and you feel worse after exercising, you may suffer from exercise intolerance.
Most people with autoimmunity see at least five doctors before they are given an actual diagnosis. Conventional doctors typically tell them they will feel better if they just exercise more and increase their intensity. While in theory there is truth to this, in reality this can worsen a patient’s symptoms until they better manage their autoimmunity and chronic illness.
What is exercise intolerance?
Conventional medicine recognizes exercise intolerance as associated with heart disease — when the heart does not adequately fill with blood. This prevents it from adequately pumping blood to the rest of the body.
We see exercise intolerance through a much broader lens in functional medicine: typically it arises in struggling with high inflammation from autoimmunity.
“It’s normal for a healthy person to feel sore or tired after a strenuous workout. However, the person with exercise intolerance will experience severe and unusual pain, fatigue, a flare up of their autoimmune symptoms, nausea, vomiting, or other abnormal effects..”
Some even “crash” and become bed ridden with flu-like symptoms.
Exercise intolerance can be demoralizing, frustrating, and humiliating for people trying to feel better. The struggle is real as our culture constantly bombards us with images of super athletes and messaging to push harder.
Why does exercise intolerance happen?
When it comes to autoimmunity, exercise intolerance happens as a result of poorly functioning mitochondria.
Mitochondria are the “energy factories” of each cell. Their role is to turn nutrients and oxygen that come into the cell into energy for the body.
Here's the bad news: mitochondria are highly sensitive to inflammation. Inflammation damages them and causes them to function not-so-well. This means you body and brain don’t function well and you feel worse.
How are you supposed to get exercise if you have exercise intolerance?
Having exercise intolerance does not mean you can never be physically active again. It just means honoring where you are and working within your limits. Our culture applauds overdoing and for the person with autoimmunity, pushing too hard and over exercising is stressful and over-training increases inflammation and can make an autoimmune condition worse.
In addition, when you have an autoimmune condition (or two or three or more), you must understand your immune system is constantly fluctuating. Stress, viruses, diet, and other factors affect inflammation. Therefore, if you work out regularly this means you may need to dial it down or take some time off. Listen to your body and make adjustments in duration, intensity, or frequency as needed.
Forget about society’s messages around fitness
Managing autoimmunity and chronic illness differs from person to person; you will NOT have the same protocol as someone else. Listening to your body can be difficult in our over-zealous health and wellness culture.
Find what works for you and makes you feel good. Healthy exercise should make you feel better and give you a natural high from the endorphins released. These endorphin releases lower inflammation and help you better manage your conditions!
Autoimmune appropriate exercises for can include walks, light weight training, gentle yoga or stretching routines, or water aerobics. Explore and look for what will be fun and interesting for you. As you start to feel better you will naturally feel inclined to increase the frequency, duration, and intensity of your workouts.
Start slow so that you are able to stay consistent and exercise every day. Once you have established that, then gradually increase intensity and duration.