Adolescent Smoking and its Effect on Aerobic Exercise Tolerance.

In brief: Twelve 16- to 18-year-old boys with a history of long-term, heavy smoking and 12 closely matched nonsmokers were studied during progressive treadmill running to exhaustion. The smokers had significantly lower endurance performance times, even though maximum values for oxygen uptake, heart rate, and systolic blood pressure were not significantly different from those in the nonsmokers. Treadmill performance was reduced in the smokers possibly because breathing discomfort limited their hyperventilatory response at maximum exertion.