What can methane in a cigarette do to your body?

Methane is a highly explosive gas. If cigarettes gave off any significant amount of methane, they would explode! The amount in cigarette smoke is of the same order as that in Earth's atmosphere (0.000179%) which, as cigarette smoke is mainly "fresh air" is probably the source of most of it in cigarette smoke.

Endurance would be my answer

Answer charlie should immediately start an exercise and diet program because all his test indicate that he is extremely obese;