Becoming nauseated or sick during or after your workouts is not uncommon. If you are accustomed to the workouts after a few sessions, the likelihood of sickness should decrease. Yet, other external factors may contribute to nausea during exercise. If you still become regularly sick during or after your workouts, even after making changes to your routine, check with your doctor to rule out other medical conditions.
Highly intense activities, especially if you are unaccustomed to them, can cause nausea. Beginning exercisers may get sick during exercise due to hormonal changes, increased blood pressure and elevated heart rate. According to the American Council on Exercise, it's best to incorporate a warm-up period before activity to allow your body to adjust to higher intensity activity and decrease the likelihood of sickness. If you are in especially cold or hot climates, extend your warm-up to at least 10 minutes. As you adapt to your routine, sickness should become less frequent.
According to a study conducted in the Appetite journal, people are more likely to feel nauseated when they exercise in a fasted state or immediately after eating. Nausea further increases if activity is highly intense or at 70 to 80 percent of a person's heart rate reserve, which measures the difference between the resting heart rate and estimated maximal heart rate. The least amount of nausea is present during light to moderate intensity exercise--about 50 to 60 percent heart rate reserve--started one hour after eating. It is recommended to eat a small meal at least one hour prior to exercise to help prevent sickness.
Hydration and Electrolytes
When you are dehydrated or over-hydrated, your electrolytes become unbalanced. This can distress your gastrointestinal track and cause sickness. Your primary electrolytes that become unbalanced through water loss are potassium and sodium. To stay properly hydrated, Competitor Network recommends weighing yourself before and immediately after a normal workout to determine fluid loss. The weight you lose is through sweat and respiration which contain sodium. Drink four ounces of water for every 15 minutes of activity to stay hydrated. During highly intense activity or workouts that last for over an hour, sip on an electrolyte drink to keep your sodium levels normal.
Some people simply experience motion sickness during exercise. If your exercise routine involves circuits with many level changes, up-and-down motions and supine to prone positions, consider changing the order of your exercises. If you have high blood pressure or take blood pressure medication, level changes can exacerbate the condition and possibly increase sickness. Try standing exercises followed by seated or supine exercises and end with prostrate exercises.