To be honest, I don't really understand what your talking about, but I think the answer is cell respiration.
False, because one of the people may already have one
Marathon’s consist of running/jogging/sprinting long distances, so first off it would be a good idea to increase stamina, which would be done by jogging everyday, increasing your distance everyday. Stretch your calf muscles upper leg muscles to avoid cramps while running too.
It is false. It slows down activity.