Physical exercise training (PET) has been considered an excellent non-pharmacological strategy to prevent and treat several diseases. There are various benefits offered by PET, especially on the immune system, promoting changes in the morphology and function of cells, inducing changes in the expression pattern of pro and anti-inflammatory cytokines. However, these changes depend on the type, volume and intensity of PET and whether it is being evaluated acutely or chronically. In this context, PET can be a tool to improve the immune system and fight various infections. However, the current COVID-19 pandemic, caused by SARS-CoV-2, which produces cytokine storm, inducing inflammation in several organs, with high infection rates in both sedentary and physically active individuals, the role of PET on immune cells has not yet been elucidated. Thus, this review focused on the role of PET on immune system cells and the possible effects of PET-induced adaptive responses on SARS-CoV-2 infection and COVID-19.

OBJECTIVES: Aerobic exercise training prevents cardiovascular risks. Regular exercise promotes functional and structural adaptations that are associated with several cardiovascular benefits. The aim of this study is to investigate the effects of swimming training on coronary blood flow, adenosine production and cardiac capillaries in normotensive rats. METHODS: Wistar rats were randomly divided into two groups: control (C) and trained (T). An exercise protocol was performed for 10 weeks and 60 min/day with a tail overload of 5% bodyweight. Coronary blood flow was quantified with a color microsphere technique, and cardiac capillaries were quantified using light microscopy. Adenine nucleotide hydrolysis was evaluated by enzymatic activity, and protein expression was evaluated by western blot. The results are presented as the means ± SEMs (p<0.05). RESULTS: Exercise training increased the coronary blood flow and the myocardial capillary-to-fiber ratio. Moreover, the circulating and cardiac extracellular adenine nucleotide hydrolysis was higher in the trained rats than in the sedentary rats due to the increased activity and protein expression of enzymes, such as E-NTPDase and 59- nucleotidase. CONCLUSIONS: Swimming training increases coronary blood flow, number of cardiac capillaries, and adenine nucleotide hydrolysis. Increased adenosine production may be an important contributor to the enhanced coronary blood flow and angiogenesis that were observed in the exercise-trained rats; collectively, these results suggest improved myocardial perfusion.

Os esteróides anabolizantes androgênicos (EAA) são sintéticos de testosterona desenvolvidos para fins terapêuticos. São também utilizados por populações fisicamente ativas, que normalmente excedem nas doses, o que potencializa danos à saúde. Para estudar alguns dos efeitos de EAA sobre o sistema cardiovascular, ratos "Wistar" foram divididos em quatro grupos: sedentário controle (SC), sedentário anabolizado (SA), treinado controle (TC) e treinado anabolizado (TA). Foram avaliados os efeitos da associação do uso de EAA (Decanoato de nandrolona - 5 mg/kg sc, 2x/sem) e do treinamento físico de natação (TFN - 60 min/dia, 5x/sem, durante 10 sem) sobre o débito cardíaco (DC) e fluxo sanguíneo basal (DCbasal, Qbasal) e após infusão do vasodilatador acetilcolina (DC Ach, Q Ach) para observar a vasodilatação endotélio dependente (QAch), razão capilar/fibra (rc/f) e expressão do fator de crescimento endotelial vascular (VEGF) em músculo sóleo (predominância de fibras oxidativas). A testosterona plasmática aumentou nos grupos com uso de EAA e foi observada bradicardia de repouso como efeito do TFN. O DC foi menor para o Grupo TA, tanto na condição basal quanto sob infusão de Ach. O Qbasal não foi diferente entre os grupos no músculo estudado. O QAch foi maior no grupo TC, entretanto, no grupo TA este efeito benéfico do TFN foi prejudicado pela associação com o EAA. Aumento da rc/f e VEGF foi observado somente no grupo TC. Estes resultados sugerem que a associação do EAA ao TFN atenua a angiogênese e arteriogênese observadas como efeito do treinamento físico aeróbio e causa prejuízo ao fluxo sanguíneo muscular, o que poderia predispor o praticante de esportes e atividades físicas e usuário destas substâncias a problemas vasculares.

Androgenic anabolic steroids (EAA) are synthetic derivatives of testosterone, used in therapeutic dosages in medical practice and in high doses by physically active people that could be health damaging. To study the effects of EAA on the cardiovascular system, Wistar rats were randomized into Sedentary Control (SC), Sedentary Steroid (SA), Trained Control (TC) and Trained Steroid (TA) groups. We evaluated the effects of swimming training (60min/day, 5x/week during 10 week) and AAS (nandrolone decanoate - 5 mg/kg sc, 2x/week) on cardiac output, basal blood flow (Qb, DC basal) and after injection of a vasodilator to observe the endothelium dependent vasodilatation (acetylcholine - Q Ach)(Q Ach, DC Ach), capillary to fiber ratio (r c/f) and vascular-endothelial growth factor expression (VEGF) in soleus muscle (oxidative fibers). Serum testosterone increased in SA and TA. Exercise training significantly decreased resting heart rate. Qb was not different among groups, and QAch was higher in TC group, however in TA group this beneficial effect of swimming exercise training was lost by association with EAA. Rc/f and VEGF were higher only in TC group. These results suggest that swimming training associated with EAA inhibit angiogenesis and arteriogenesis observed as effects of aerobic training, and impairs the red skeletal muscle blood flow which predispose physically active AAS users to vascular diseases.