Effects of Exercise Training on Improving the Immune System of Elderly at the Time of COVID-19: a Systematic Review

3] Clinical features of ... [4] Clinical characteristics of imported cases ... [5] Clinical, laboratory and ... [6] Clinical characteristics of 113 ... [7] Effect of teaching the ... [8] Effect of 12 weeks of chosen ... [9] Immune function in sport ... [10] Evaluation of effective motivators ... [11] The study of physical ... [12] The effect of pilates training ... [13] Impact of aerobic training on CD25 ... [14] Effect of aerobic training on levels ... [15] Influence of 3 Months resistance ... [16] Effects of aerobic training ... [17] The effect of circuit resistance ... [18] The effects of eight weeks ... [19] Monocyte and T-cell responses ... [20] Effect of moderate exercise ... [21] The Effects of walking exercise ... [22] Effects of 12 months of exercise ... [23] Effect of resistance training ... [24] Effects of resistance training ... [25] Moderate exercise training ... [26] Effects of 6 months of moderate ... [27] Chronic resistance exercise ... [28] A crosssectional study ... [29] The effects of resistance ... [30] Moderate exercise may attenuate ... [31] Impact of aerobic exercise versus ... [32] Circuit resistance training improved ... [33] Changes in functional fitness ... [34] Age-related effects in T cell ... [35] Perforins in human cytolytic ... [36] CD28 expression in T cell aging ... [37] Age-dependent modifications ... [38] The capacity of the natural ligands ... [39] Carbohydrate intake during ... [40] Moderateintensity regular exercise ... [41] A role of suppressor of cytokine ... [42] Exercise traininginduced adaptations ... [43] Gerontology in the developing ... [44] The effect of body composition ... [45] Exercise training-induced lowering ... [46] Effect of exercise training intensity ... [47] Cholesterol and atherosclerosis ... [48] Sustained increase in aortic ... [49] Salivary IgA secretion rate in ... [50] Stay home: Role of physical exercise ... AimsThis study aimed to investigate the effect of exercise training to improve the immune system of the elderly at the time of COVID-19.Information & Methods This systematic review study was performed on articles published between 1999 and 2020, and their target group was elderly.Keywords were searched and evaluated by three people in PubMed, Scopus, Science Direct, Google Scholar, Magiran, and SID databases.Twenty-two articles were selected for research.Findings According to most studies' results, the leukocyte population decreased significantly or did not change in response to training.In most studies, the levels of T cells (CD3+), helper T cells (CD4+), killer T cells (CD8+), natural killers (CD56+), and B cells (CD19+) did not change.CD28+CD4+ cells after intervention either increased significantly or did not change in some studies.Naive T cells (CD45RA+) and memory T cells (CD45RO+) did not change in the studies.Natural killer cell cytotoxic activity (NKCA) also increased significantly or did not change.Interleukin-6 and tumor necrosis factor-alpha decreased significantly in all related studies, but on the other hand, interleukin-10 increased significantly.The amount of C-reactive protein decreased significantly in the two studies and did not change in the other two studies.Intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule (VCAM-1), and endothelin-1 decreased significantly in investigations.Salivary IgA secretion rate increased significantly in two studies.Salivary IgA concentration increased in two studies and did not change in the other two studies.Salivary IgA flow increased in one study and did not change in another study.Conclusion According to the results, regular moderate-intensity exercise training reduces inflammation and improves some safety indicators in the elderly.With immune system improvement through exercise training in the elderly, the ability of the elderly may increase for encountering COVID-19 infection, and the risk of acquiring severe COVID-19 and hospitalization and mortality rates related to this disease may reduce in the elderly.