Why Do I Feel Sick When Exercising?

I remember the first time I ever took a cardio kickboxing class, I was in for a rude awakening. I thought I was in good shape, but 10 minutes in I started to feel lightheaded, a little dizzy, and then nausea set in. This was the first time that this had happened to me, and I was shocked because I thought to feel sick from exercise was just something that happened to people in those crazy Crossfit Instagram videos who do burpees until they pass out. Unfortunately, I was wrong, and I found out the hard way. Ever since the day that I spent most of my kickboxing class with my head out the back door, I started looking into why this happens, and if there is a way to prevent it. 

The Why

Exercise-induced nausea is actually a common occurrence. There are a few reasons why you may feel sick when you push yourself really hard while exercising, or if you haven’t exercised in a long time and start a new routine. One reason this happens is that when you are exercising, your body pushes blood to the muscles that need it the most. Which, you guessed it, is not your stomach and digestive system. This is a mechanism of the sympathetic nervous system, or in other words the “fight or flight” behavior of your body. Our bodies developed this response so that when we were running away from a hungry lion, it could use all of its resources and energy on the muscles that were needed for survival. Fortunately, most of us don’t have to run away from a lion to survive anymore. Unfortunately, our bodies still go into that, “fight or flight” response when we push it into higher levels of stress.

Another reason why you may feel sick during exercise could be related to your diet. If you eat a meal too close, or too early before your workout, it can lead to being nauseated during your workout. Generally, I would recommend eating between 90 minutes and 30 minutes prior to your workout. Everyone is different, and everyone’s body reacts differently, so you may have to experiment with what time you eat before your workout. What you eat matters as well. I recommend not eating a meal or snack that is higher in fat, because fat is slower digesting than carbohydrates and protein. If you are in the process of digesting a higher fat meal or snack, and the blood leaves your digestive track, there is a greater chance that you will feel sick.

Hydration is also a major factor in how you feel while you exercise. To be adequately hydrated, you should be consuming about half of your body weight in ounces of water each day. This should be spread out through the entire day, and not consumed immediately before your workout. A lot of people will start a workout while in a state of dehydration because they do not hydrate properly on a daily basis, which then leads to them chugging water throughout their workout. This could lead to feeling sick throughout the workout.

The Solution

My first word of advice for you is to ease into any new exercise routine, especially if you are deconditioned and have not worked out in a long time. Pace yourself until you can build up a base of conditioning, so you do not send your body into an extreme “fight or flight” response when you workout. 

Timing your nutrition is also key. As I stated earlier, everyone is different and will respond in different ways. However, a general rule of thumb is to give yourself an hour after consuming a snack before you start exercising. You should also make sure to drink between 16-20 ounces of water about an hour before your workout. This will help ensure that you have some level of proper hydration.

You DO NOT need to puke for it to be a good workout.

This is a common misnomer that, unfortunately, a lot of personal trainers and coaches believe in. In this age of social media, the amount of pictures and videos of clients that were just crushed during a workout is sickeningly (no pun intended) prevalent. A personal trainer or coach who brags about crushing his/her clients, and uses that as a way to show off how hard their workouts are, is flat out uneducated. Exercise is supposed to be an activity that leads to a positive feeling. It is not meant to make you pass out on the floor and throw up on yourself. In fact, this will actually hinder your results and decrease your drive to want to exercise again. There are absolutely no positive benefits to making someone vomit while exercising. I am not saying that you shouldn’t push yourself hard while working out, however, being pushed to the point of getting sick is in no way necessary!