There are several potential causes for exercise-related nausea, many of which are easy to fix. If you don't have any food in your stomach-say, if you exercise in the morning before breakfast-you'll be more likely to feel light-headed, dizzy or nauseated with exertion. So before breaking a sweat, down a sport drink mixed with some water or eat a small snack. (A combo of carbs and protein between 150 and 175 calories, such as 1 tablespoon peanut butter on an apple, is good.) On the flip side, having too much food in your belly can also make you queasy. When you exercise, your muscles demand more blood, diverting some away from organs like the stomach-which can slow digestion and leave you feeling ill. Pushing yourself too hard with your workouts can also be to blame. If none of these seems to be your situation, or if you feel green often, check with your doctor, who can look for less common causes, such as certain heart conditions and infections.
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