A TEN MINUTES RESTING INTERVAL AFTER SMOKING SHOULD BE TAKEN FOR SAFTY EXERCISE PRESCRIPTION

Abstract

We aimed to investigate the acute effects of cigarette smoking on cardiovascular systems during exhaustive exercise, comparing different time conditions of smoking exposure. Study subjects consisted of 3 male and 2 female habitual smokers (S; 25.0±3.4 yrs), and 2 male and 3 female non-smokers (NS; 22.7±1.8 yrs). All the participants performed symptom-limited maximal graded exercise on a cycle ergometer under three various conditions; non-smoking(control),5 min. after(S5) and 10 min.after(S10) smoking a cigarette. Heart rate(HR) and blood pressure(BP) were recorded every one-minute before, through, and after exercise. Rate pressure product(RPP), which is often used a parameter of myocardial oxygen uptake, was also calculated using obtained HR and systolic blood pressure(SBP). As to acute responses of HR or BP, both S and NS did not show significant differences among control, S5 and S10 with each other. In NS, however. ANOVA demonstrated significant differences in RPP after 8min.pedaling, the RPP of S5(27,900±4,174bpm.mmHg) was higher than those of control(24,028±3,952bpm. mmHg, p < 0.05) and of S10(24,532±2,627bpm. mmHg, p < 0.05) respectively. This intensity of emiently increased RPP appearance was equaled to 10.7±1.7METs, that is, also just above the anaerobic threshold(AT) levels in all the subjects. It is accepted that the cardiovascular risks derived from exercise stress tends to be higher over the AT point, where sympathetic tone just begin to be alerted. This finding observed in NS is thought to be due to combined effects of not only exercise but smoking only one cigarette. It also suggests that even in habitual smokers who are accustomed to the exposure of nicotine and carbon monoxide, higher demanded exercise immediately after smoking lager amount of cigarettes would be considered strenuous to cardiovascular systems. From the viewpoint of preventive cardiology, we insist on being keen to RPP response above the AT level intensity. In conclusion, at least 10 minutes resting interval after smoking should be taken for the safety exercise prescription.