AnswerVery bad! What is inhaled from smokes goes directly into your lungs. Your blood has a path it takes, into heart, through lungs, back to other side of heart, out to body. So your blood gets the chemicals smoking leaves behind and takes them to your heart. If you love your heart, do not smoke.
also, it increases the risks of a heart attack. the nicotine raises heart rate which is very bad. it makes your body work harder than it needs to. smoking causes heart diseases.
Carbon monoxide , in cigarettes, affects the heart by reducing the amount of oxygen the blood cells can carry to the heart and other tissues. This would mean that Susan wouldn't have enough oxygen to breathe properly during the race.
It also damages the lining of the arteries, increasing the build up of plaque that leads to atherosclerosis, which is a condition in which fatty material collects along the walls of arteries. This fatty material thickens, hardens and may eventually block the arteries. This would been the blood couldn't get through to carry the oxygen, again.
A word of advice, don't smoke, it will ruin your life! :(