Exercise-induced nausea is exaggerated by eating

This study was conducted to determine whether and under what circumstances exercise causes nausea. Twelve healthy volunteers (20-37 years), including six athletes, participated in the study. Subjects were studied on seven occasions. Each subject performed low and high-intensity exercise without eating, immediately after eating a beef patty and 60 min after eating. Besides these exercise experiments, effect of meal on nausea was studied in each subject for 180 min without exercise. Exercise was done on a bicycle ergometer for 60 min at 40-50% maximal heart rate reserve and 20 min at 70-80% maximal heart rate reserve. Subjects were tested for nausea by visual analogue scales. Both low and high-intensity exercise caused nausea. Scores for nausea were greater during exercise at fasting state and immediately after eating than those without exercise (p<0.05 during low-intensity exercise, and p<0.01 during high-intensity exercise). Immediately after eating, scores for nausea were greater during high-intensity exercise than during low-intensity exercise (p<0.05). During high-intensity exercise, scores for nausea were greater immediately after eating than without eating (p<0.05). There were no differences in ratings for nausea between the sexes in any of the experimental conditions. Training did not decrease exercise-induced nausea. In conclusion, exercise causes nausea, the severity of which is related to exercise intensity and food intake, but not sex differences nor physical training.