Exercise Induced Nausea: Causes and Corrections

Nutrition and how the human body absorbs and responds is unique from individual to individual, influenced by outside variables (i.e. heat, humidity and intensity), and has to be validated by trial and error. Let’s review some basic elements that may cause nausea and some suggestions on how to reduce or eliminate associated symptoms.

Cause #1: Pre Race Anxiety & Race Intensity

Everyone experiences anticipation and stress on race day. Pre-race stress can lead to feelings of nausea and may have a negative effect on your race day nutritional plans. This is caused by the fact that body has to “decide” which is more important: digestion for fuel or maintaining core body temperature.

  • Digestion – Blood and water are needed in the digestion process to convert your food to stored sugar.
  • Performance – Your racing efforts require blood (for oxygen to be carried to the working muscles) along with water (to be diverted to your skin to rid yourself of internal heat).

You can see how this creates a “stress” on your entire body as it attempt to prioritize what to do: break down food for fuel or sweat to maintain your core body temperature. The solution is to consume easily digestible food that maintain blood sugar levels within the blood.

Cause #2: Food Timing & Types

Low blood sugar levels are frequently associated with dizziness and nausea. Maintaining a consistent blood sugar level has a significant impact on your energy and performance. Because the body stores carbohydrates in limited quantities – 60-90 minutes of stored energy in the muscles and liver – it is important to eat throughout the day. To keep your blood sugar level stable and energy stores high, aim to eat four to six small meals throughout your race day.

Give yourself two hours between your pre-race meal and start time. This will allow enough time for your body to break down, absorb and purge completely. On race day, choose food items that are easy to digest (see below).

The following sources of carbohydrates (stored in the muscles as glycogen) should be consumed throughout the day: whole wheat grains, rye, stone ground bread, oatmeal, lentils, beans, peas, asparagus, broccoli, fresh ripe fruit (specifically apples, pears, apricots & bananas), high quality cereals, whole wheat pasta, brown rice, couscous and quinoa. Following your race, carbs that are beneficial for recovery include white potatoes, watermelon, white rice, noodles, cereal, waffles and pancakes.

For controling appetite and speeding up recovery after your race, immediately consume a carbohydrate-protein beverage to replace depleted sugar and repair torn down muscle tissue. The ideal recovery nutrition source is 150 to 200 calories at a mixture of 3:1 of carbohydrates and protein. By consuming this carb-protein drink within 30 minutes of your race, your body takes advantage of a highly active enzyme (glycogen synthase) responsible for replenishing depleted sugar within the muscle and liver. This will result in a higher level of replenishment, setting you up for higher levels of output in your next race.

Good sources of protein include salmon, tuna, lean deli meat, mixed nuts (avoid peanuts), beans, lentils, tofu, whey, eggs, milk, yogurt, cheese, cottage cheese, and ice cream (if you are not lactose intolerant). Avoid excessive fiber and fatty meals in the day leading up to the race as your food needs to be easy to digest. As mentioned above, stick to carbohydrate-based meals with lean protein and a small amount of fat. The low fiber residue will lessen the severity of G.I. (gastro-intestinal) disturbances on race day.

Cause #3: Fluid Timing, Types and Amounts

The key to proper hydration is not the act of drinking water and sports drinks that contain sugar and electrolytes, but rather the absorption of what you drink. The solution is to drink at the right time with the correct concentration of carbohydrates and electrolytes specific to your sweat rate.

Sip consistently on a sports drink that has a 4-6% carbohydrate concentration and a solid electrolyte profile (Energy Fuel) to ensure that you are maintaining your hydration levels.

One hour before your race, consume 8 to 10 ounces of ice cold sports drink (cold absorbs better than warm). Approximately 15 minutes before your race, consume 4-6 ounces of your ice cold sports drink. Immediately following your race, consume 8 to 10 ounces of your sports drink. When you have raced your last race of the day, consume your protein-carbohydrate beverage as mentioned previously.

Note that drinking too much water can lead to a state of hyponatremia (low blood sodium) which can increase nausea related symptoms. Drinking too little water can lead to a state of dehydration which can also cause nausea related symptoms. The key is to determine the optimum amount of fluids to consume. How do we do this?

Using a copy of Coach Robb’s Sweat Rate Calculator, you can determine your sweat rate given your intensity level, duration, air temperature and humidity. By determining your sweat rate, you can determine how much fluid you need to consume on race day.

Choose the right sports drink. Research science has shown that the key to maintaining high levels of energy from a sports drink is determined by how quickly the body can convert the sugar to energy. Complex carbohydrates have to be broken down over a long period of time which results in a slower delivery of energy. During high intensity racing (and in high temperatures), the digestive process is slowed down, as mentioned earlier because the body is working hard to deliver oxygen and rid itself of heat. When you compound a slowed digestive system with complex carbohydrates, you have delayed delivery of energy for racing.

The solution is to use sports drinks that have a 4-6% concentration rate, which are made from simple sugars and have electrolytes added for better absorption. A product that I helped develop, Energy Fuel, has this exact profile and has been tested for over a year with great results on the track. The sugar in Energy Fuel (cane sugar) is absorbed passively (without the need of your digestive system to break it down) and will not only sustain your energy, but also help prevent any backing up in the stomach (and associated discomforts).

Cause #4: Cold & Hot Environments

Both hot and cold weather places stress on your body by elevating your heart rate. This places a demand on your stored sugar levels and begins to shut down your digestive process. The solution is to choose your racing gear accordingly.

During hot weather as your body strives to rid itself of heat, you will notice that your heart rate will be elevated and sweating will start immediately. Wear gear that is light in color, has wick away characteristics and vented.

During cold weather, your body is constantly trying to conserve heat and stay warm (hence the shivering). Wear throw away clothing to the start line and discard as you pull into the gate.

Other possible irritants  are alcohol, caffeine, spices, artificial sweeteners and ibuprofen which can create irritation in some people. The body’s various systems (circulatory, respiratory, etc.) become more sensitive to any irritants when under physical emotional or mental stress. Racing tends to present all three of these types of stress. Identifying anything that might create symptoms before you get to the races will result in better race day results.

What else can you do?

As always, speak with your physician about anti-nausea medication that may offer some relief when raing or training hard. Probiotics may assist with G.I. disturbances as well as being of assistance to general immune health.

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