Feeling Nauseous After a High Intensity Workout: Is it normal and why does it happen?

Feeling quite sick and wanting to vomit post workout is known as exercise induced nausea and is very normal to experience. It also doesn’t mean you are unfit!

It’s a frequent misunderstanding that being nauseous during or after a workout means that you are unfit. The severity of nausea experienced is dependent on the exercise intensity & food intake.

If poor fitness isn't the cause, then what is?

Exercise is designed to push us to our extremes, so there are many things happening in the body that can cause vomiting.

It’s thought that nausea may be a product of lactic acidosis which is when your blood becomes more acidic than what your body can handle from other increasing levels of lactic acid during exercise. A reduction in the blood's pH can bring on vomiting to try and regulate the body’s acid-base balance. 

Lactate is a product that is used to create more energy, but unfortunately, if the muscles produce more than what they can handle, it builds up in the blood. When you reach the maximum amount of lactate your body can handle, it is called lactate threshold. 

When the lactate levels increase, so do acidity levels which causes the brain to sense a toxic environment wanting to get rid of the toxicity. It does this by causing you to vomit. 

Is food another cause?

In order to supply the muscles with more blood, the body must transport the flow of blood away from your stomach and intestines, slowing down the process of digestion. Eating a meal before commencing exercise, causes the food to “sit” there resulting in an unsettled stomach. This may make you feel nauseous and want to vomit during the workout. 

Some pointers to try and reduce exercise-induced nausea

  1. Avoid eating food high in fiber before commencing exercise
  2. Avoid slow digesting foods such as protein, fat and milk products before commencing exercise to promote faster, more efficient gastric emptying
  3. Avoid having foods and/or drinks that contain high levels of fructose
  4. Make sure you are well hydrated before and during your exercise session to reduce the risk of dehydration which can possibly worsen exercise-induced nausea symptoms
  5. Eat foods rich in carbohydrates with a higher water content


  1. de Oliveira, E. P., Burini, R. C., & Jeukendrup, A. (2014). Gastrointestinal Complaints During Exercise: Prevalence, Etiology, and Nutritional Recommendations. Sports Medicine, 44(S1), 79–85.
  2. Kondo, T., Nakae, Y., Mitsui, T., Kagaya, M., Matsutani, Y., Horibe, H., & Read, N. (2001). Exercise-induced nausea is exaggerated by eating. Appetite, 36(2), 119–125.
  3. Right, E. (2021, May 14). Why Do You Feel Nauseous After All-Out Exercise? Exercise Right.
  4. Valeur, J., & Julsrud, J. (2013). Vomiting: a physiological response to acidosis? Scandinavian Journal of Gastroenterology, 48(9), 1103–1104.