Introduction
Smoking is one of the major causes of morbidity and mortality worldwide. Smokers have an increased risk of developing autonomic dysfunction, which can be evaluated by both heart rate variability (HRV) and heart rate recovery (HRRec). Most studies involving this analysis is performed on adults of advanced age and in condition of rest.
Objectives
To compare the cardiac autonomic activity, at rest and during exercise in young men, smokers and non-smokers.
Methods
Thirty-two young volunteers (aged 22.0 ± 2.8 years) were divided into two groups: the smoking group (SG, n = 15) and non-smokers (NSG, n = 17). We carried out the Cooper test and HRV analysis by heart rate monitor Polar(r)s810i, at rest and during exercise and HRRec.
Results
In SG, 73% were classified as having a "very low" level of nicotine dependence according to the Fargeström's questionnaire. Classification of active and very active by the IPAQ questionnaire accounted for over 50% of sample in both groups. There were no significant differences between groups in HRV, both at rest and during exercise. However, in each group, difference has been noted in most HRV indexes from rest to exercise. During Cooper test there were no significant differences in mean HR, HRpeak and HRRec between groups, but a better functional capacity was noted in NSG in the distance walked (2050.2 ± 300.0 vs. 1780.3 ± 390.4m, p = 0.036).
Conclusion
The SG showed lower functional capacity and parasympathetic activation during exercise, besides lower HRV indexes during rest, suggesting an early impairment in cardiac autonomic modulation.
exercise; smoking; primary dysautonomias
