AEROBIC CAPACITY - DIFFERENCES BETWEEN SM OKERS AND NONSMOKERS - MODIFICATIONS AFTER SMOKING WITHDRAWAL

The purpose of this study is to determine the aerobic capacity in a gr oup of smokers and to carry out a prospective study of the changes in cardiorrespiratory and metabolic response to exercise after smoking wi thdrawal. An aerobic capacity test was performed in 90 smokers and 30 non-smokers. Afterwards, the smokers were included in a smoking withdr awal program. One year later, the aerobic capacity test was repeated i n those individuals who were able to stop smoking. The initial study o f the aerobic capacity during exercise showed that smokers had signifi cantly lower values of maximal oxygen uptake per kg body weight (VO2 m ax./kg) (28.7 +/- 8 vs. 35.1 +/- 7 ml/kg/min) (p<0.001), work time (5. 8 +/- 2.6 vs. 7.5 +/- 3.1 min) (p<0.01) and work load (1.1 +/- 0.3 vs. 1.4 +/- W/kg) (p<0.001) under aerobic conditions. Aerobic capacity te st performed one year after smoking withdrawal in those who were able to stop smoking showed a significant increase in VO2 max./k, (35.5 +/- 6.1 vs. 31.1 +/- 5.5) (p<0.05), work time (8.1 +/- 3.2 vs. 5.8 +/- 3. 2 min) (p<0.05) and work load (1.5 +/- 0.4 vs. 1.1 +/- 0.4 W/kg) (p<0. 01) under aerobic conditions. No differences were observed in the aero bic capacity test performed on the ten subjects who did not stop smoki ng. From these data we suggest that tobacco consumption produdes impai rment of the aerobic capacity that can be reverted, at least in part, after smoking withdrawal.