THE EFFECTS OF CHRONIC SMOKING AND NEGATIVE SLOPE CYCLING EXERCISE ON MUSCLE DAMAGE

Abstract

The aim of this study was to examine the effects of chronic smoking on muscle damage following a negative sloped cycling exercise. A group of 20 healthy, sedentary, male subjects aged 17 to 35 years volunteered for the study. They were classified as smokers who had smoked 20.5 ± 2.4 cigarettes a day for at least 4.8 ± 1.0 years (n=10) and non-smokers (n=10). Each subject performed an isometric peak torque test, submaximal test and maximal test. In another occasion, they performed a 10% negative slope cycling exercise for 30 min at 60% of their maximal work capacity. Range of motion (ROM), delayed onset of muscle soreness (DOMS), plasma creatine kinase activity (CK) and malondialdehyde (MDA) levels were evaluated before, immediately after, and on the 1st , 2nd , 3rd and 7th days following cycling exercise. Repeated measures ANOVA and Wilcoxon signed rank test were used for statistical analyses. Significant (p<0.05) increases were observed in MDA concentrations immediately after cycling exercise in both groups, with no significant differences between the groups. Plasma CK levels, ROM and DOMS measurements were not different among the groups, either. Isometric peak torque decreased (p<0.05) immediately following exercise in both groups, without any significant group effect. It is possible to conclude that no clear muscle damage could be produced in the exercise model used in this study, and that smoking had no further effects on muscle damage.