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.