Abnormal cardiac repolarization in anabolic androgenic steroid users carrying out submaximal exercise testing

Long-term effects of doping with anabolic steroids during adolescence on physical and mental health

BACKGROUND

Systematic doping programs like in the GDR were applied in adolescent competitive athletes to induce supramaximal athletic performance. The substances had adverse somatic and psychological effects. The psychological development of the young athletes was impaired and they suffered in adulthood from long-term effects and secondary diseases even years after the doping period.

METHOD

The study compared three groups: competitive athletes with doping (I), competitive athletes without doping (II) and persons with no sports activities (III). Somatic and psychological diseases were analyzed to identify the adverse effects of doping in the most vulnerable phase of development in adolescence. Participants were asked to supply a patient history and completed a questionnaire with standardized psychological tests.

RESULTS

The doping cohort had a higher rate of somatic diseases, psychological disorders and social and professional difficulties. The differences were gender-specific with males more often having impaired liver function, depression, tumors and difficulties associated with the workplace . The doping group reported more emotional and physical neglect during childhood. They proved to be less optimistic but more pessimistic, to perceive less social support and to be more depressive. The study identified less extraversion and more neuroticism. Posttraumatic stress disorder (PTSD) occurred in a small number of participants in the doping group. Doping is associated with psychiatric variables. Predictors were the subscale identifying feelings of the Toronto alexithymia scale 20 (TAS-20), the sense of coherence and the Beck depression inventory 2 (BDI-II) and the Beck depression inventory (BDI).

CONCLUSION

Physical and psychosocial effects imply correlation with the application of doping substances but might not only be due to the side effects of these substances but also caused by the system, which exerts great psychological pressure and stress during adolescence, a highly vulnerable phase.

Forensic Post-Mortem Investigation in AAS Abusers: Investigative Diagnostic Protocol. A Systematic Review

Anabolic–androgenic steroids (AASs) are a group of synthetic molecules derived from testosterone and its precursors. AASs are widely used illicitly by adolescents and athletes, especially by bodybuilders; AASs are among the most used drugs for improving physical performance, as well as for aesthetic purposes. The use of AASs by professional and recreational athletes is increasing worldwide. This review focused on deaths related to AAS abuse and to investigation of the autopsy results and histopathological findings using a rigorous methodology protocol covering: a complete autopsy, histological analysis, and a broad toxicological investigation. Moreover, we aimed to define an investigative diagnostic protocol supporting forensic pathologists during the post-mortem investigation of AAS abusers. This review was conducted using PubMed Central and Google Scholar databases to find articles published between 1 January 1968 and 30 June 2021, using the following key terms: “(anabolic-androgenic steroids) AND (autopsy); (anabolic-androgenic steroids) AND (forensic)”. A total of 939 articles were screened and 926 did not meet the inclusion criteria. In conclusion, 14 articles were included in this systematic review, reporting 137 fatal cases of AAS abuse in total. The histopathologic studies showed myocardial damage characterized by myocyte hypertrophy, focal myocyte damage with myofibrillar loss, interstitial fibrosis, mostly subepicardial, and small vessel disease. Indeed, in AAS-related cases, autopsy plays a pivotal role in the study of AAS adverse effects and organ damage related to their use or abuse. This systematic review aimed to define a specific workflow in death cases related to AASs, suggesting important future insights to better clarify sudden deaths related to AASs, such as the use of miRNAs. The forensic community needs a unified approach in cases of suspected death related to the use of AASs. There are several occasions to apply this workflow, for example in cases of death of bodybuilders and of young people who die in gymnasiums or during sports activities.

Sudden Cardiac Death in Anabolic-Androgenic Steroid Users: A Literature Review

Background and objectives: Anabolic-androgenic steroids (AASs) are a group of synthetic molecules derived from testosterone and its related precursors. AASs are widely used illicitly by adolescents and athletes, especially by bodybuilders, both for aesthetic uses and as performance enhancers to increase muscle growth and lean body mass. When used illicitly they can damage health and cause disorders affecting several functions. Sudden cardiac death (SCD) is the most common medical cause of death in athletes. SCD in athletes has also been associated with the use of performance-enhancing drugs. This review aimed to focus on deaths related to AAS abuse to investigate the cardiac pathophysiological mechanism that underlies this type of death, which still needs to be fully investigated. Materials and Methods: This review was conducted using PubMed Central and Google Scholar databases, until 21 July 2020, using the following key terms: “((Sudden cardiac death) OR (Sudden death)) AND ((androgenic anabolic steroid) OR (androgenic anabolic steroids) OR (anabolic-androgenic steroids) OR (anabolic-androgenic steroid))”. Thirteen articles met the inclusion and exclusion criteria, for a total of 33 reported cases. Results: Of the 33 cases, 31 (93.9%) were males while only 2 (61%) were females. Mean age was 29.79 and, among sportsmen, the most represented sports activity was bodybuilding. In all cases there was a history of AAS abuse or a physical phenotype suggesting AAS use; the total usage period was unspecified in most cases. In 24 cases the results of the toxicological analysis were reported. The most detected AASs were nandrolone, testosterone, and stanozolol. The most frequently reported macroscopic alterations were cardiomegaly and left ventricular hypertrophy, while the histological alterations were foci of fibrosis and necrosis of the myocardial tissue. Conclusions: Four principal mechanisms responsible for SCD have been proposed in AAS abusers: the atherogenic model, the thrombosis model, the model of vasospasm induced by the release of nitric oxide, and the direct myocardial injury model. Hypertrophy, fibrosis, and necrosis represent a substrate for arrhythmias, especially when combined with exercise. Indeed, AAS use has been shown to change physiological cardiac remodeling of athletes to pathophysiological cardiac hypertrophy with an increased risk of life-threatening arrhythmias.

Anabolic Steroids and Cardiovascular Outcomes: The Controversy

Anabolic steroids (AS) are synthetic derivatives of the male sex hormone testosterone. The use of AS is not limited to bodybuilders and athletes, but non-athletes also use them. It is used to enhance athletic performance, induce muscle hypertrophy, and augment male sexual characteristics. AS use is associated with a wide range of side effects and potential cardiovascular complications. In this article, we have searched the available literature to investigate the association between AS use and cardiovascular disease (CVD). The results revealed that AS was linked to lipid metabolism derangements, hypertension, coagulation disorders, and cardiomyopathy. We concluded, based on the relevant data, that there was evidence that suggests an association with CVD, primarily myocardial infarction, fatal arrhythmias, and cardiomyopathy in AS users. The general population should be informed of the risk. Also, methods of primary and secondary prevention should be implemented to mitigate the risk of CVD secondary to AS.

Anabolic androgenic steroid abuse in the United Kingdom: An update

Anabolic androgenic steroids (AASs) are prescribed for medical conditions related to low testosterone. Abuse of AASs has surged as they become recognised as potent image enhancement drugs. The primary goal of most abusers is to obtain a more attractive outward appearance. Abuse is complex. There are a vast range of AAS substances illegally available, the nature of their true composition is difficult to evaluate. Users follow dosing patterns which incorporate a number of different AASs, in addition to other pharmaceutical substances believed to complement the desired physical effects or manage unwanted effects. Animal work and medical case reports suggest potential to cause serious hepatotoxicity, plus possible neurotoxicity, nephrotoxicity and damage to the cardiovascular and reproductive systems. As the long-term AASs users reach maturity, further controlled experimentation, with larger sample sizes, is required. Data gathering should be directed towards the most vulnerable group of AAS users, females and adolescent boys.

Combined effects of exercise training and high doses of anabolic steroids on cardiac autonomic modulation and ventricular repolarization properties in rats

Several studies have reported that high doses of synthetic anabolic androgenic steroids (AAS) can have serious negative effects on health, including the cardiovascular system. The aim of this study was to evaluate the combined effects of AAS and exercise training on ventricular repolarization and cardiac autonomic modulation in rats. Male Wistar rats were allocated into 4 groups: sedentary rats treated with vehicle, sedentary rats treated with nandrolone decanoate, swimming-trained rats treated with vehicle, and swimming-trained rats treated with nandrolone decanoate. Ventricular repolarization was evaluated by electrocardiographic analysis of QT interval and QT dispersion. Cardiac autonomic modulation was assessed by heart rate variability. Our results show that AAS increased QT interval and QT dispersion in sedentary rats treated with nandrolone decanoate as compared to sedentary rats treated with vehicle, indicating AAS-induced ventricular repolarization abnormalities. When rats treated with nandrolone decanoate were subjected to concomitant exercise training, ventricular repolarization was normalized. On the other hand, AAS-induced reduction in cardiac parasympathetic modulation was not prevented by exercise training. In conclusion, AAS produced cardiac autonomic dysfunction and ventricular repolarization disturbances in rats. Combining an exercise training protocol during the AAS treatment attenuated the ventricular repolarization abnormalities and did not prevent cardiac autonomic dysfunction.

Cardiac electrical and contractile disorders promoted by anabolic steroid overdose are associated with late autonomic imbalance and impaired Ca2+ handling

AIM

Investigate cardiac electrical and mechanical dysfunctions elicited by chronic anabolic steroid (AS) overdose.

METHODS

Male Wistar rats were treated with nandrolone decanoate (DECA) or vehicle (CTL) for 8 weeks. Electrocardiography and heart rate variability were assessed at weeks 2, 4, and 8. Cardiac reactivity to isoproterenol was investigated in isolated rat hearts. Action potential duration (APD) was measured from left ventricular (LV) muscle strips. L-type Ca²⁺ current (I_CaL), and transient outward potassium current (I_to) were recorded by whole-cell patch-clamp in LV cardiomyocytes. Sarcoplasmic reticulum (SR) Ca²⁺ mobilization and Ca²⁺-induced contractile response sensitivity were evaluated in skinned cardiac fibers. Muscarinic type 2 receptor (M₂R), β₁-adrenergic receptor (β₁AR), sarcoplasmic Ca²⁺ ATPase (SERCA-2a), type 2 ryanodine receptor (RyR2), L-type Ca²⁺ channel (CACNA1), Kv4.2 (KCND2), and Kv4.3 (KCND3) mRNA expression levels were measured by quantitative RT-PCR.

RESULTS

Compared with CTL group, DECA group exhibited decreased high frequency band power density (HF) and increased low frequency power density (LF), Cardiac M₂R mRNA level was decreased. QTc interval at 2nd, 4th, and 8th week as well as APD₃₀ and APD₉₀ were increased by DECA. I_to density was decreased, while I_CaL density was increased by DECA. SR Ca²⁺ loading and release were decreased by DECA, while contractile sensitivity to Ca²⁺ was increased versus CTL group.

CONCLUSION

DECA overdose induced cardiac rhythmic and mechanical abnormalities that can be associated with autonomic imbalance, up-regulated I_CaL and down-regulated I_to, abnormal SR Ca²⁺ mobilization, and increased contractile sensitivity to Ca²⁺.

Acute interruption of treatment with nandrolone decanoate is not sufficient to reverse cardiac autonomic dysfunction and ventricular repolarization disturbances in rats

Anabolic androgenic steroids are a class of synthetic compounds derived from testosterone, eventually used by athletes, to improve physical performance. However, anabolic steroids can also modify normal cardiovascular function. Thus, we investigated cardiac electrophysiological and autonomic abnormalities in rats, through a electrocardiographic variability protocol during and after interruption of administration of nandrolone decanoate (DECA) anabolic steroid. Twenty male Wistar rats (60-70 days old) received DECA (10 mg. kg^-1i.m) once a week or vehicle, during eight weeks. Electrocardiogram was recorded in conscious rats by a noninvasive method, and time and domain analysis of heart rate variability as well as electrocardiogram intervals (QTc / QTd) were performed. Body mass was lower in treated rats compared to control after 4th and 8th weeks, but not at the end of 14th week. QTc and QTd were longer in DECA group compared to control on 4th, 8th, 11th, but equal on 14th week. Cardiac autonomic dysfunction (vagal attenuation) was present on DECA group after 4th week and did not normalize after interruption of treatment. The animals of DECA group showed a correlation between attenuated parasympathetic modulation and increased correct QT interval. Our data allow us to conclude that long-term treatment with DECA impairs autonomic cardiac physiology, predisposing to cardiovascular risk and sudden death, and interruption of administration does not recovery the normality immediately.

Prolonged androgenic anabolic steroid (AAS) induced QT interval shortening: a suitable screening tool?

Androgenic anabolic steroid (AAS) abuse is associated with changes in cardiac electrophysiology. Recently heart rate corrected QT interval (QTc) has been suggested as a method of screening for AAS use in athletes despite conflicting reports. This study aimed to further investigate the effect of AAS on QTc in a cohort of long-term AAS users in whom the affects may be more pronounced. Using a cross-sectional cohort design with AAS using resistance trained athletes (AS n = 15) and a group of non-AAS using resistance trained, age matched controls (C n = 15). AS had a long history of AAS use (18 ± 2 yrs) and AS and C both had >19 years of resistance training. Participants underwent a resting electrocardiogram (ECG), from which, the QTc interval was calculated using the Bazett formula. The main outcome measure was significant differences in mean corrected QTc between groups. A secondary outcome was to calculate a QTc that best differentiated between C and AS. Results indicated that QTc was shorter in AS than in C (382.0 ± 21.01 ms versus 409 ± 18.77 ms for AS and C respectively p < 0.001). Chi squared analyses revealed a greater incidence of QTc < 380 ms in AS versus C p < 0.01, specificity 93% sensitivity 60%). In conclusion these results supports previous findings that AAS use causes a reduction in QTc, however, the specificity and sensitivity in our sample is lower than reported previously and precludes use as a screening tool.

The Effect of Chronic Anabolic-Androgenic Steroid Use on Tp-E Interval, Tp-E/Qt Ratio, and Tp-E/Qtc Ratio in Male Bodybuilders

BACKGROUND

The chronic consumption of androgenic anabolic steroids has shown to cause atrial arrhythmias. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate repolarization dispersion measured from the 12-lead surface electrocardiogram (including Tp-e interval, Tp-e/QT ratio, and Tp-e/cQT ratio) in bodybuilders who are using anabolic androgenic steroids (AAS).

METHODS

We selected a population of 33 competitive bodybuilders, including 15 actively using AAS for ≥ 2 years (users) and 18 who had never used AAS (nonusers), all men.

RESULTS

QT, cQT, QTd, cQTd, JT, and cJT were significantly increased in AAS users bodybulders compared to the nonusers (all P < 0.001). Tp-e interval, Tp-e/QT ratio, and Tp-e/cQT ratio were also significantly higher in AAS user group compared to the nonuser group (all P < 0.001). QRS duration was not different between the groups. There were negative correlation between E(m) and Tp-e, Tp-e/QT ratio, Tp-e/cQT ration (r = -0.657, P < 0.01; r = -0.607, P = 0.02; r = -0.583, P = 0.02; respectively).There were also negative correlation between S(m) and Tp-e, Tp-e/QT ratio, Tp-e/cQT ration (r = -0.681, P < 0.01; r = -0.549, P = 0.03; r = -0.544, P = 0.023; respectively).

CONCLUSION

In conclusion, we have presented a strong evidence suggesting that Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were increased in AAS users, which suggest that there might be a link between AAS use and ventricular arrthymias and sudden death.

Adverse health consequences of performance-enhancing drugs: an Endocrine Society scientific statement

Despite the high prevalence of performance-enhancing drug (PED) use, media attention has focused almost entirely on PED use by elite athletes to illicitly gain a competitive advantage in sports, and not on the health risks of PEDs. There is a widespread misperception that PED use is safe or that adverse effects are manageable. In reality, the vast majority of PED users are not athletes but rather nonathlete weightlifters, and the adverse health effects of PED use are greatly underappreciated. This scientific statement synthesizes available information on the medical consequences of PED use, identifies gaps in knowledge, and aims to focus the attention of the medical community and policymakers on PED use as an important public health problem. PED users frequently consume highly supraphysiologic doses of PEDs, combine them with other PEDs and/or other classical drugs of abuse, and display additional associated risk factors. PED use has been linked to an increased risk of death and a wide variety of cardiovascular, psychiatric, metabolic, endocrine, neurologic, infectious, hepatic, renal, and musculoskeletal disorders. Because randomized trials cannot ethically duplicate the large doses of PEDs and the many factors associated with PED use, we need observational studies to collect valid outcome data on the health risks associated with PEDs. In addition, we need studies regarding the prevalence of PED use, the mechanisms by which PEDs exert their adverse health effects, and the interactive effects of PEDs with sports injuries and other high-risk behaviors. We also need randomized trials to assess therapeutic interventions for treating the adverse effects of PEDs, such as the anabolic-androgen steroid withdrawal syndrome. Finally, we need to raise public awareness of the serious health consequences of PEDs.

Ventricular structure, function, and focal fibrosis in anabolic steroid users: a CMR study

PURPOSE

Anabolic steroid (AS) misuse is widespread amongst recreational bodybuilders; however, their effects on the cardiovascular system are uncertain. Our aim was to document the impact of AS use on cardiac structure, function and the presence of focal fibrosis using the gold standard cardiovascular magnetic resonance imaging (CMR).

METHODS

A cross-sectional cohort design was utilised with 21 strength-trained participants who underwent CMR imaging of the heart and speckle-tracking echocardiography. Thirteen participants (30 ± 5 years) taking AS for at least 2 years and currently on a "using"-cycle were compared with age and training-matched controls (n = 8; 29 ± 6 years) who self-reported never having taken AS (NAS).

RESULTS

AS users had higher absolute left ventricular (LV) mass (220 ± 45 g) compared to NAS (163 ± 27 g; p < 0.05) but this difference was removed when indexed to fat-free mass. AS had a reduced right ventricular (RV) ejection fraction (AS 51 ± 4 % vs. NAS 59 ± 5 %; p < 0.05) and a significantly lower left ventricular E':A' myocardial tissue velocity ratio [AS 0.99(0.54) vs. NAS 1.78(0.46) p < 0.05] predominantly due to greater tissue velocities with atrial contraction. Peak LV longitudinal strain was lower in AS users (AS -14.2 ± 2.7 % vs. NAS -16.6 ± 1.9 %; p < 0.05). There was no evidence of focal fibrosis in any participant.

CONCLUSIONS

AS use was associated with significant LV hypertrophy, albeit in-line with greater fat-free mass, reduced LV strain, diastolic function, and reduced RV ejection fraction in male bodybuilders. There was, however, no evidence of focal fibrosis in any AS user.

Effects of Short-term Exercise Training on Cardiorespiratory Fitness of Male Adults with Myocardial Infarction

[Purpose] The purpose of this study was to determine the effects of short-term exercise training on the cardiorespiratory fitness (CRF) of individuals suffering from myocardial infarction. [Subjects] A total of 60 participants were divided into experimental (EXP; n=30, mean age 56.7 ± 2.8 years, body mass 80.7 ± 10.7 kg, body height 171.9 ± 7.2 cm) and control (CON; n=30, mean age 56.5 ± 3.1 years, body mass 84.4 ± 12.4 kg, body height 171.5 ± 12.4 cm) groups. [Methods] The members of the EXP group took part in an organized daily physical exercise program (Monday through Sunday), for a period of 3 weeks. The exercise program consisted of 60 min daily specialized fitness exercises with an intensity ranging from 55-70% of the maximum heart rate, which was determined by test on a bicycle ergometer. The effects of the exercise were monitored by means of the following parameters: maximum oxygen uptake (VO2peak), resting heart rate, systolic blood pressure and diastolic blood pressure. [Results] The results indicate statistically significant post-exercise improvements in heart rate, relative oxygen uptake and systolic blood pressure, among the members of the EXP group. The results indicate that at the initial measurement of cardiorespiratory fitness no statistically significant differences were found between the groups at the multivariate level (Wilk's λ=0.83), while statistically significant differences in the cardiorespiratory fitness were found at the final measurement (Wil's λ=0.430). [Conclusion] The obtained results indicate that the exercise program, which lasted for a period of 21 days, though shorter in duration than other programs still led to statistically significant changes in the CRF of individuals suffering from MI.

The blockade of angiotensin AT1 and aldosterone receptors protects rats from synthetic androgen-induced cardiac autonomic dysfunction

AIM

This study aimed to evaluate the combined effects of exercise and antagonists of the angiotensin II and aldosterone receptors on cardiac autonomic regulation and ventricular repolarization in rats chronically treated with nandrolone decanoate (ND), a synthetic androgen.

METHODS

Thirty male Wistar rats were divided into six groups: sedentary, trained, ND-treated, trained and ND-treated, trained and treated with both ND and spironolactone, and trained and treated with both ND and losartan. ND (10 mg kg(-1) weekly) and the antagonists (20 mg kg(-1) daily) of the angiotensin II AT1 (losartan) and aldosterone (spironolactone) receptors were administered for 8 weeks. Exercise training was performed using a treadmill five times each week for 8 weeks. Following this 8-week training and treatment period, electrocardiogram recordings were obtained to determine the time and frequency domains of heart rate variability (HRV) and corrected QT interval (QTc).

RESULTS

Nandrolone decanoate treatment increased the QTc interval and reduced the parasympathetic indexes of HRV (RMSSD, pNN5 and high-frequency power) in sedentary and trained rats. The ratio between low- and high-frequency power (LF/HF) was higher in ND-treated groups. Both losartan and spironolactone treatments prevented the effects of ND on the QTc interval and the HRV parameters (RMSSD, pNN5, high-frequency power, and the LF/HF ratio).

CONCLUSION

Our results show that chronic treatment with a high dose of ND induces cardiac parasympathetic dysfunction and disturbances in ventricular repolarization in both sedentary and exercised rats. Furthermore, inhibiting the renin-angiotensin-aldosterone system using losartan, or spironolactone, prevented these deleterious effects.

Androgen abuse and increased cardiac risk

The objectives of this article were to review the anabolic androgen steroids, specifically the direct and indirect effects on the cardiovascular system of the individuals who use them, and to summarize the evidence regarding the effects of androgens on the cardiovascular system. A search of the English-language scientific literature from 1976 to March 2012 was performed primarily by searching the MEDLINE and Embase databases and Google. Anabolic androgenic steroids are associated with direct effects such as cardiac muscle hypertrophy and myocardial fibrosis and indirect effects, including dyslipidemia, hypertension, arrhythmia, and myocardial infarction. It is likely that chronic exposure to these agents can result in significant alterations in the cardiovascular system, and their safety has not been fully established.

Anabolic androgenic steroid use is associated with ventricular dysfunction on cardiac MRI in strength trained athletes

BACKGROUND

Uncertainty remains about possible cardiac adaptation to resistance training. Androgenic anabolic steroids (AAS) use plays a potential role and may have adverse cardiovascular effects.

OBJECTIVE

To elucidate the effect of resistance training and of AAS-use on cardiac dimensions and function.

PARTICIPANTS

Cardiac magnetic resonance (CMR) were performed in 156 male subjects aged 18-40 years: 52 non-athletes (maximum of 3 exercise hours/week), 52 strength-endurance (high dynamic-high static, HD-HS) athletes and 52 strength (low dynamic-high static, LD-HS) trained athletes (athletes ≥ 6 exercise hours/week). 28 LD-HS athletes denied and 24 admitted to AAS use for an average duration of 5 years (range 3 months-20 years).

RESULTS

No significant differences were found between non-athletes and non-AAS-using LD-HS athletes. AAS-using LD-HS athletes had significantly larger LV and RV volumes and LV wall mass than non-AAS-using LD-HS athletes, but lower than HD-HS athletes. In comparison to all other groups AAS-using LD-HS athletes showed lower ejection fractions of both ventricles (LV/RV EF 51/48% versus 55-57/51-52%) and lower E/A ratios (LV/RV 1.5/1.2 versus 1.9-2.0/1.4-1.5) as an indirect measure of diastolic function. Linear regression models demonstrated a significant effect of AAS-use on LV EDV, LV EDM, systolic function and mitral valve E/A ratio (all ANOVA-tests p<0.05).

CONCLUSIONS

Strength athletes who use AAS show significantly different cardiac dimensions and biventricular systolic dysfunction and impaired ventricular inflow as compared to non-athletes and non-AAS-using strength athletes. Increased ventricular volume and mass did not exceed that of strength-endurance athletes. These findings may help raise awareness of the consequences of AAS use.

Cardiac autonomic dysfunction in anabolic steroid users

This study aimed to evaluate if androgenic-anabolic steroids (AAS) abuse may induce cardiac autonomic dysfunction in recreational trained subjects. Twenty-two men were volunteered for the study. The AAS group (n = 11) utilized AAS at mean dosage of 410 ± 78.6 mg/week. All of them were submitted to submaximal exercise testing using an Astrand-Rhyming protocol. Electrocardiogram (ECG) and respired gas analysis were monitored at rest, during, and post-effort. Mean values of VO2 , VCO2 , and VE were higher in AAS group only at rest. The heart rate variability variables were calculated from ECG using MATLAB-based algorithms. At rest, AAS group showed lower values of the standard deviation of R-R intervals, the proportion of adjacent R-R intervals differing by more than 50 ms (pNN50), the root mean square of successive differences (RMSSD), and the total, the low-frequency (LF) and the high-frequency (HF) spectral power, as compared to Control group. After submaximal exercise testing, pNN50, RMSSD, and HF were lower, and the LF/HF ratio was higher in AAS group when compared to control group. Thus, the use of supraphysiological doses of AAS seems to induce dysfunction in tonic cardiac autonomic regulation in recreational trained subjects.