When Working Out Makes You Sick to Your Abdomen: What to Know About Train-Induced Nausea
By Anne R. Crecelius, Dayton University
You do it! You will exercise and benefit from all of the benefits of exercise that have been drilled into your head.
So kick your heart out or run like you’re escaping a zombie horde. You feel completed on cloud nine until … your stomach starts to twist. You may even feel dizzy. Your feelings of success have turned into agony when you struggle with nausea.
Exercise-related nausea is as common as exercise-induced gastrointestinal (GI) problems in general, which can affect up to 90% of endurance athletes.
Why is this happening and, more importantly, how can you prevent it?
The cause: competing requirements
When you exercise, the skeletal muscles in your legs and arms contract. To be able to work most efficiently, they need oxygen. Your heart muscle contracts and the blood flow to your body increases. The hemoglobin molecules in your red blood cells carry oxygen to your working muscles.
To maximize the amount of blood delivered to active muscles, your body directs blood away from inactive areas – like your intestines. This distraction is monitored by the “fight or flight” branch of your nervous system. It is called the sympathetic nervous system and causes some blood vessels to narrow and restrict blood flow. You have no conscious control over this process called vasoconstriction.
But your contracting skeletal muscles have a special power to maintain blood flow. You can resist the call for vasoconstriction, which helps direct blood away from inactive areas. This resistance to the action of the sympathetic nervous system is known as “functional sympatholysis”. Physiologists like me continue to work to understand the specific mechanisms by which this can happen.
Why does restricting blood flow to the gut cause stress?
Relative ischemia, or poor blood flow, can have different effects. It can change how cells can take in what has been digested and how broken down foods move through the intestines. Taken together, the changes create an uncomfortable feeling that you may know all too well.
The lack of blood flow is especially difficult when the digestive system is actively trying to break down and ingest food. A major reason exercise nausea can be worse immediately after you eat, especially if the pre-workout meal is high in fat or concentrated carbohydrates.
The cure: moderation and modification
Exercising if you have stomach cramps or run to the bathroom is no fun. So what can you do to limit symptoms or get rid of them when they occur?
- Moderate your exercise intensity. Nausea is more common with intense exercise, where the competing demands on blood flow are the highest. Especially if you are new to training, gradually increasing your training intensity should help minimize the likelihood of GI exposure.
- Change your practice. Some evidence suggests that certain exercises, such as B. cycling can put the body in a position that is more likely to cause bowel problems. Try different types of training or combinations of different modes to achieve your fitness goals while minimizing discomfort. Make sure you warm up and cool down properly to avoid rapid changes in your body’s metabolism.
- Change what and when you eat and drink. Drink enough! You’ve probably heard it before, but drinking enough is one of the best ways to avoid GI problems during and after your workout, especially in hot or humid environments. However, it is possible to hydrate too much. Aim for about a quart of fluids per hour, including some low-carb and low-sodium sports drinks for vigorous exercise. It may take some experimentation with different foods and when to eat them to find out what works best for you and your training goals. You can also incorporate foods like ginger, crackers, and coconut water that can help calm your stomach.
The restriction: when to seek help
While exercise-induced nausea is uncomfortable, it is generally not a major health issue. Most symptoms should go away within an hour of stopping exercise. If the problems persist for a long period of time after exercise or with any exercise, it is worth talking to your doctor.
Sometimes, GI exposure can actually lead to vomiting during or after exercise. Unfortunately, if you vomit, you will likely feel better, but you will also need to rehydrate and replenish the lost nutrition.
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When starting an exercise program or looking to increase the intensity of your current workout, it is often a wise approach to seek advice from trained professionals who can tailor a plan to meet your needs. Exercise physiologists or certified personal trainers can provide exercise programs of appropriate intensity, and registered dietitians can discuss individual nutritional needs and strategies. Your GP can help you check for more serious medical problems and should be briefed on your exercise routine as well.
Anne R. Crecelius, Associate Professor of Health and Exercise Science, University of Dayton
This article is republished by The Conversation under a Creative Commons license. Read the original article.