What are some physical benefits to be derived from aerobics?

Some physical benefits that derived from aerobics are : increase in the quality of the cardiovascular system , increase in lung muscle , heart muscles, incresae in blood flow, and reduce some body fat. While weightlifting is good in targeting specific muscle, aerobics tend to work all part of our body.

Smoking damages the respiratory system by inhalation of a foreign substance, that is absorbed and residue is left behind on our lungs sponge like substance. the gas that is inhaled also increase your blood pressure and dilates your blood vessels. also the process of inhaling and exhaling the smoke it causes irritation to the throat and mouth. smoking can cause lung cancer and other respiratory and circulatory diseases. 

Pe.dometer would be the most useful to you for monitoring heart rate.