Abstract
The purpose of this study was to evaluate whether AAS abuse can induce cardiac autonomic dysfunction in trained individuals after a session. Employing a quasi-experimental design, 17 healthy men were divided into two groups: users of AAS (N-7), who reported self-administration for at least two years and non-users of AAS (N-10). All subjects performed an acute strength-training session consisting of three sets of 10 repetitions at 70% of 1RM for four exercises (bench press, leg press, rowing and leg extension), with an inter set rest interval of 60 seconds. HRV measurements were taken before and during a 60-minute post-exercise recovery period. Results showed that AAS users had lower values for standard deviation of the NN intervals and root mean squared successive differences when compared to the non-AAS users before the resistance exercise. However immediately after the resistance training, all indexes in the time domain, non-linear and symbolic analysis were similar between AAS and NAAS. We conclude that the use of AAS is consistent with a dysfunction of the autonomic system, resulting in an increase of the sympathetic component and a corresponding decrease of the parasympathetic component.