Varies: There is no specific dangerous heart rate during exercise. How fast your heart beats with exercise depends on a number of factors, especially your conditioning. If you are healthy, a heart reate in the 170's or even higher may be ok and tolerated.
Motion sickness caused by video games, sometimes called simulator sickness, is caused when there is a disconnect between what your eyes are seeing and what your body is feeling.
Motion sickness is something that we hear a lot about these days, and many people want to know exactly what it is. In its simplest form motion sickness is fatigue and nausea, along with disorientation, that is commonly brought on by motion of the head.