A tornado is a dangerous natural disaster. Tornados are formed by air from one side and the other by merging into eachother and they will start rotation like a cyclinder. the more the air is narrow and streached the faster it gets. these can go up to 300 mph. they can destruct any type of building, trees or vehicles miles away.
The heart must beat faster during exersise because by increasing the heart rate the body is able to increase cardiac output and deliver the necessary blood flow to the mucles