Visually induced motion sickness is one of the detrimental effects of video images on human psychosomatic state. Several studies for alleviating this effect have been cumulated in recent years. One of the studies reported that people with high heart rate tended to be immune to the motion sickness. This fact motivated us to assume that the increase of subjects' heart rate through physical exercise before video watching could prevent them from the motion sickness. Then we investigated the effects of video exposure with such pre-exercise on the motion sickness. First we recorded psychosomatic state of 23 volunteers using the simulator sickness questionnaire (SSQ) before and after watching extremely unpleasant video images of a mountain-bike ride capable of visually inducing motion sickness. Then we classified them into nausea and non-nausea groups, based on SSQ evaluation. Subjects' heart rate in nausea group increased gradually during video exposure, while that in non-nausea group was nearly constant. By imposing a 5-minute pre-exercise on 12 subjects in nausea group before video exposure, 10 subjects became immune to the motion sickness, demonstrating that the pre-exercise would be efficient for alleviating the motion sickness. In addition subjects' heart rate in nausea group remained at a higher level during video exposure than at rest, whereas it returned to the rest level immediately after the pre-excise without video exposure.