Relation between cigarette smoking and ventilatory threshold in the Japanese.

The link between cigarette smoking and ventilatory threshold (VT) was investigated. We used data for 407 men and 418 women not taking medication. Habits of cigarette smoking were obtained through interviews by well-trained staff. The influence of cigarette smoking on oxygen uptake, work rate, and heart rate at VT was evaluated. Oxygen uptake at VT in women and work rate at VT in men with cigarette smoking were significantly lower than in subjects without cigarette smoking after adjusting for age. The differences of parameters at VT did not reach significant levels after adjusting for age and exercise habits in both sexes. However, in women without exercise habits, there was significant difference of oxygen uptake at VT between women with and without cigarette smoking after adjusting for age [cigarette smoking (+): 11.5 ± 1.8 ml/kg/min, cigarette smoking (-): 12.4 ± 2.1 ml/kg/min, p = 0.0006]. The number of cigarettes smoked per day and the Brinkman Index were not clearly correlated with oxygen uptake at VT. A combination of promoting exercise habits and prohibiting cigarette smoking might be recommended for improving the aerobic exercise level, especially in women.