1. Introduction
n late December 2019, a disease called coronavirus disease 2019 (COVID-9) was identified in Wuhan, China, which spread rapidly around the world. Its virus was first found in seafoods in Wuhan, China [1, 2]. COVID-9 can severely affect the immune system and affect many tissues, especially the lungs, by causing cytokine storms in the body [8]. On the other hand, it has been shown that exercise can increase the function of the immune system [15]. People are still active at different intensities during the COVID-9 pandemic. This study aims to review the effect of different intensities of exercise on the immune system, and consequently on COVID-9.
2. Materials and Methods
This is a review study. The search was conducted in Scopus ،ISC, PubMed, Google Scholar, MagIran, and Noor databases on related studies published from 1995 to 2020 by using following keywords: Coronavirus, COVID-9, exercise and coronavirus, exercise and immune system, high-intensity exercise and immune system, moderate-intensity exercise and immune system, low-intensity exercise and immune system. The inclusion criteria were: publishing in Persian or English, and in journals with higher impact factor or reputable national journals. The exclusion criteria were: publishing in blacklisted or hijacked journals, publishing at conferences, and being duplicate or unrelated study.
3. Results 
With the outbreak of COVID-9, many physiological changes occurred in the body including a impairment in the immune system and a rapid increase in obesity, depression and cardiovascular problems [10]. It has been shown that exercise can reduce the risk of these problems [13, 14]. However, the intensity of exercise is a major factor. High-intensity exercise can increase cortisol and lower the immune system function, while moderate-intensity exercise can improve immune function, reduce weight, and so on [15]. In general, it can be said that exercise is an effective strategy to make positive changes in the physiological process of the body during the COVID-9 pandemic. Studies have shown that exercise can increase endorphins and reduce depression. In a study, sudden stop of exercise caused professional athletes to become depressed; that is why researchers stated that moderate-intensity exercise can be very effective [35].
Preliminary epidemiological data have shown that cardiovascular diseases are very common following a significant increase in disease severity and mortality in people who are inactive and obese. Cardiovascular benefits of regular exercise include a reduction in resting heart rate and blood pressure, improved respiration, weight loss, and other metabolic changes that can lead to improved lipid profiles and glucose tolerance [43]. Undoubtedly, these factors are important and justify the constant emphasis on regular exercise as a major part of prevention and treatment goals. Studies have also reported that moderate-intensity exercise to be a very good factor in increasing fat oxidation. High-intensity exercise can also inhibit lipolysis. In this regard, Khoramipour et al. هn their review study stated that the highest rate of fat oxidation occurs at low to moderate intensities between 35 to 65% VO2max [50]. Therefore, it can be said that moderate-intensity exercise during the COVID-9 pandemic can cause weight loss.
Exercise can act like a medicine in the body. Numerous studies have shown that exercise and physical activity can have anti-inflammatory effects [56, 57, 58, 59] and help improve the immune system and increase T cells in the body [56]. For athletes who perform moderate to high-intensity exercises, it is recommended to use liquid carbohydrates during competition to prevent a weakened immune system and increased interleukin-10 level [61]. In this regard, regular exercise can have an anti-inflammatory effect on the body, such that exercise has been shown to improve the immune response to influenza vaccine in the elderly [55]
4. Discussion and Conclusion
Due to the outbreak of COVID-9 and increased home stay, performing exercise along with simple movements can improve the function of the immune and cardiovascular systems. According to numerous reports of the effect of high-intensity exercises on lowering the function of the immune system, it is better to perform moderate-intensity exercises (for 30-45 min). It is also recommended to control the house humidity during indoor exercise indoors. Finally, people with severe colds or COVID-9 are better to refrain from exercise until they are fully recovered.

Ethical Considerations
Compliance with ethical guidelines
In writing this article, ethical principles were considered in accordance with the instructions of the National Ethics Committee and the COPE regulations.

Funding
This study was approved by the Vice-Chancellor for Research and Technology, Tarbiat Modares University.

Authors' contributions
The authors observed the criteria of the International Committee of Medical Journal Editors (ICMJE).

Conflicts of interest
The authors declare no conflict of interest.

Acknowledgements
The authors would like to thank the Research Center of Tarbiat Modares University (TMU).


References

1. World Health Organization. Laboratory testing of human suspected cases of novel coronavirus (‎‎‎nCoV)‎‎‎ infection: Interim guidance [Internet]. 2020 [Updated 2020 January 10]. Available from: https://apps.who.int/iris/handle/10665/330374
2. Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med. 2020; 382(18):1708-20. [DOI:10.1056/nejmoa2002032]
3. Zheng J. SARS-CoV-2: An emerging coronavirus that causes a global threat. Int J Biol Sci. 2020; 16(10):1678-85. [DOI:10.7150/ijbs.45053] [PMCID]
4. Nikpouraghdam M, Jalali Farahani A, Alishiri G, Heydari S, Ebrahimnia M, Samadinia H, et al. Epidemiological characteristics of coronavirus disease 2019 (COVID-19) patients in IRAN: A single center study. J Clin Virol. 2020; 127:104378. [DOI:10.1016/j.jcv.2020.104378]
5. Takian A, Raoofi A, Kazempour-Ardebili S. COVID-19 battle during the toughest sanctions against Iran. Lancet. 2020; 395(10229):1035-6. [DOI:10.1016/S0140-6736(20)30668-1]
6. World Health Organization. Coronavirus Disease (COVID-19) Dashboard [Internet]. 2020 [Updated 2021 May 15]. Available from: https://covid19.who.int/
7. Li G, Fan Y, Lai Y, Han T, Li Z, Zhou P, et al. Coronavirus infections and immune responses. J Med Virol. 2020; 92(4):424-32. [DOI:10.1002/jmv.25685]
8. Shamsi MM, Hassan ZM, Gharakhanlou R. Exercise-induced chaperokine activity of hsp70: Possible role in chronic diseases. In: Asea AAA,  Kaur P, editors. Chaperokine Activity of Heat Shock Proteins. Germany: Springer; 2019. https://link.springer.com/chapter/10.1007/978-3-030-02254-9_10
9. Woods JA, Hutchinson NT, Powers SK, Roberts WO, Gomez-Cabrera MC, Radak Z, et al. The COVID-19 pandemic and physical activity. Sports Med Health Sci. 2020; 2(2):55-64. [DOI: 10.1016/j.smhs.2020.05.006]
10. Hammami A, Harrabi B, Mohr M, Krustrup P. Physical activity and coronavirus disease 2019 (COVID-19): Specific recommendations for home-based physical training. Manag Sport Leis. 2020:1-6. [DOI:10.1080/23750472.2020.1757494]
11. Chen P, Mao L, Nassis GP, Harmer P, Ainsworth BE, Li F. Coronavirus disease (COVID-19): The need to maintain regular physical activity while taking precautions. J Sport Health Sci. 2020; 9(2):103-4. [DOI:10.1016/jjshs.2020.02.001] [PMCID]
12. Brooks SK, Webster RK, Smith LE, Woodland L, Wessely S, Greenberg N, et al. The psychological impact of quarantine and how to reduce it: Rapid review of the evidence. Lancet. 2020; 395(10227):912-20. [DOI:10.1016/S0140-6736(20)30460-8]
13. Monteiro CA, Conde WL, Matsudo SM, Matsudo VR, Bonseñor IM, Lotufo PA. A descriptive epidemiology of leisure-time physical activity in Brazil, 1996-1997. Rev Panam Salud Publica. 2003; 14(4):246-54. [DOI:10.1590/s1020-49892003000900005]
14. Burton NW, Turrell G. Occupation, hours worked, and leisure-time physical activity. Prev Med. 2000; 31(6):673-81. [DOI:10.1006/pmed.2000.0763]
15. Abel T, Graf N, Niemann S. Gender bias in the assessment of physical activity in population studies. Soz Praventivmed. 2001; 46(4):268-72. [DOI:10.1007/BF01593182]
16. Martínez-González MA, Varo JJ, Santos JL, De Irala J, Gibney M, Kearney J, et al. Prevalence of physical activity during leisure time in the European :union:. Med Sci Sports Exerc. 2001; 33(7):1142-6. [DOI:10.1097/00005768-200107000-00011]
17. Gomes VB, Siqueira KS, Sichieri R. [Physical activity in a probabilistic sample in the city of Rio de Janeiro]. Cad Saude Publica. 2001; 17(4):969-76. [DOI:10.1590/s0102-311x2001000400031]
18. Booth FW, Roberts CK, Thyfault JP, Ruegsegger GN, Toedebusch RG. Role of inactivity in chronic diseases: Evolutionary insight and pathophysiological mechanisms. Physiol Rev. 2017; 97(4):1351-402. [DOI:10.1152/physrev.00019.2016]
19. Sullivan M, Moore M, Blom LC, Slater G. Relationship between social support and depressive symptoms in collegiate student athletes. J Study Sports Athlete Educ. 2020; 14(3):192-209. [DOI:10.1080/19357397.2020.1768034]
20. Venkatasamy VV, Pericherla S, Manthuruthil S, Mishra S, Hanno R. Effect of physical activity on insulin resistance, inflammation and oxidative stress in diabetes mellitus. J Clin Diagn Res. 2013; 7(8):1764-6. [DOI:10.7860/JCDR/2013/6518.3306]
21. Liu K, Zhou R, Wang B, Chen K, Shi LY, Zhu J-D, et al. Effect of green tea on glucose control and insulin sensitivity: A meta-analysis of 17 randomized controlled trials. Am J Clin Nutr. 2013; 98(2):340-8. [DOI:10.3945/ajcn.112.052746]
22. Perry SA, Coetzer R, Saville CWN. The effectiveness of physical exercise as an intervention to reduce depressive symptoms following traumatic brain injury: A meta-analysis and systematic review. Neuropsychol Rehabil. 2020; 30(3):564-78. [DOI:10.1080/09602011.2018.1469417]
23. Laurens C, Bergouignan A, Moro C. Exercise-released myokines in the control of energy metabolism. Front Physiol. 2020; 11:91. [DOI:10.3389/fphys.2020.00091]
24. Simpson RJ, Campbell JP, Gleeson M, Krüger K, Nieman DC, Pyne DB, et al. Can exercise affect immune function to increase susceptibility to infection? Exerc Immunol Rev. 2020; 26:8-22. [PMID]
25. Tian D, Meng J. Exercise for prevention and relief of cardiovascular disease: Prognoses, Mechanisms, and Approaches. Oxid Med Cell Longev. 2019; 2019:3756750. [DOI: 10.1155/2019/3756750]
26. Emerenziani GP, Ferrari D, Marocco C, Greco EA, Migliaccio S, Lenzi A, et al. Relationship between individual ventilatory threshold and maximal fat oxidation (MFO) over different obesity classes in women. PLoS One. 2019; 14(4):e0215307. [DOI:10.1371/journal.pone.0215307]
27. Bersaoui M, Baldew S-SM, Cornelis N, Toelsie J, Cornelissen VA. The effect of exercise training on blood pressure in African and Asian populations: A systematic review and meta-analysis of randomized controlled trials. Eur J Prev Cardiol. 2020; 27(5):457-72. [DOI:10.1177/2047487319871233]
28. Voet NB, van der Kooi EL, van Engelen BG, Geurts AC. Strength training and aerobic exercise training for muscle disease. Cochrane Database Syst Rev. 2019; 12(12):CD003907. [DOI:10.1002/14651858.CD003907.pub5]
29. Brooks SK, Webster RK, Smith LE, Woodland L, Wessely S, Greenberg N, et al. The psychological impact of quarantine and how to reduce it: Rapid review of the evidence. Lancet. 2020; 395(10227):912-920. [DOI:10.1016/S0140-6736(20)30460-8]
30. Toresdahl BG, Asif IM. Coronavirus disease 2019 (COVID-19): Considerations for the competitive athlete. Sports health. 2020; 12(3):221-4. [DOI:10.1177/1941738120918876]
31. González-Sanguino C, Ausín B, Castellanos MÁ, Saiz J, López-Gómez A, Ugidos C, et al. Mental health consequences during the initial stage of the 2020 Coronavirus pandemic (COVID-19) in Spain. Brain Behav Immun. 2020; 87:172-6. [DOI:10.1016/j.bbi.2020.05.040]
32. Szabo A, Griffiths MD, Demetrovics Z. Psychology and exercise. In: Bagchi D, Nair S,  Sen CK, editors. Nutrition and enhanced sports performance : Muscle building, endurance, and strength. United States: Academic Press; 2018. https://www.amazon.com/Nutrition-Enhanced-Sports-Performance-Endurance/dp/0128139226
33. Arent SM, Walker AJ, Arent MA. The effects of exercise on anxiety and depression. Tenenbaum G, Eklund RC, editors. Handbook of sport psychology.  United States: John Wiley & Sons, Inc; 2020. [DOI:10.1002/9781119568124.ch42]
34. Parfitt G, Hughes S. The exercise intensity–affect relationship: Evidence and implications for exercise behavior. J Exerc Sci Fit. 2009; 7(2):S34-41. [DOI:10.1016/S1728-869X(09)60021-6]
35. Zhao JL, Jiang WT, Wang X, Cai ZD, Liu ZH, Liu GR. Exercise, brain plasticity, and depression. CNS Neurosci Ther. 2020; 26(9):885-95. [DOI:10.1111/cns.13385]
36. Gorzi A, Rajabi H,  Rajabi H, Azad A, Molanouri Shamsi M, Hedayati M. [Effect of concurrent, strength and endurance training on hormones, lipids and inflammatory characteristics of untrained men (Persian)]. IJEM. 2012; 13(6):614-29. https://www.sid.ir/en/journal/ViewPaper.aspx?id=275650
37. Furnham A, Badmin N, Sneade I. Body image dissatisfaction: gender differences in eating attitudes, self-esteem, and reasons for exercise. J Psychol. 2002; 136(6):581-96. [DOI:10.1080/00223980209604820]
38. McDonald K, Thompson JK. Eating disturbance, body image dissatisfaction, and reasons for exercising: Gender differences and correlational findings. Int J Eat Disord. 1992; 11(3):289-92. [DOI:10.1002/1098-108X(199204)11:3<289::AID-EAT2260110314>3.0.CO;2-F]
39. Prichard I, Tiggemann M. Objectification in fitness centers: Self-objectification, body dissatisfaction, and disordered eating in aerobic instructors and aerobic participants. Sex roles. 2005;53(1-2):19-28. [DOI:10.1007/s11199-005-4270-0]
40. Jackson EM. Stress relief: The role of exercise in stress management. ACSMs Health Fit J. 2013; 17(3):14-9. [DOI:10.1249FIT.0b013e31828cb1c9]
41. Bozkurt B, Kovacs R, Harrington B. HFSA/ACC/AHA statement addresses concernsre: Using RAAS antagonists in COVID-19 [Internet] 2020 [Updated 2020 March 17]. Availeble from: https://www.acc.org/latest-in-cardiology/articles/2020/03/17/08/59/hfsa-acc-aha-statement-addresses-concerns-re-using-raas-antagonists-in-covid-19
42. Shao Z, Schuster A, Borowski AG, Thakur A, Li L, Tang WHW. Soluble angiotensin converting enzyme 2 levels in chronic heart failure is associated with decreased exercise capacity and increased oxidative stress-mediated endothelial dysfunction. Transl Res. 2019; 212:80-8. [DOI:10.1016/j.trsl.2019.06.004]
43. Channon KM. Exercise and cardiovascular health: New routes to reap more rewards. Cardiovasc Res. 2019; 116(5):e56-8. [DOI:10.1093/cvr/cvz264]
44. Bhaskarabhatla KV, Birrer R. Physical activity and diabetes mellitus. Compr Ther. 2005; 31(4):291-8. [DOI:10.1385/comp:31:4:291]
45. Nystoriak MA, Bhatnagar A. Cardiovascular effects and benefits of exercise. Front Cardiovasc Med. 2018; 5:135. [DOI:10.3389/fcvm.2018.00135]
46. Marcus MD, Levine MD, Kalarchian MA, Wisniewski L. Cognitive behavioral interventions in the management of severe pediatric obesity. Cogn Behav Pract. 2003; 10(2):147-56. [DOI:10.1016/S1077-7229(03)80023-8]
47. Tayebi SM, ahmadi hekmatikar A, Ghanbari-Niaki A, Fathi R. [Ghrelin behavior in exercise and training (Persian)]. Razi J Med Sci. 2020; 27(1):85-111. http://rjms.iums.ac.ir/article-1-5803-en.html
48. Ahmadi SM, Fathi M, RashidLamir A, Aminian F. [Effects of 8 weeks aerobic training on plasma ghrelin level and ghrelin lymphocyte gene expression in elderly men (Persian)]. Salmand. 2019; 13(4):494-505. [DOI: 10.32598/SIJA.13.4.494]
49. Bird L. Exercise lowers leptin and leukocytosis. Nat Rev Immunol. 2020; 20(1):2-3. [DOI: 10.1038/s41577-019-0253-1]
50. Khoramipour K, Ahmadi Hekmatikar A, Sotvan H. [A brief overview of fatmax and MFO in exercise (Persian)]. Razi J Med Sci. 2020; 27(3):49-59. http://rjms.iums.ac.ir/article-1-5959-fa.html
51. Khosravi N, Hanson E, Farajivafa V, Agha-Alinejad H, Haghighat S, Molanouri Shamsi M, et al. [Changes in monocyte populations following acute aerobic exercise in breast cancer survivors (Persian)]. Int J Behav Develop. 2018; 11(1):7-16. http://ijbd.ir/article-1-659-en.html
52. Owen N, Sparling PB, Healy GN, Dunstan DW, Matthews CE, editors. Sedentary behavior: emerging evidence for a new health risk. Mayo Clin Proc. 2010; 85(12):1138-41. [DOI: 10.4065/mcp.2010.0444 ]
53. Guo Y, Qiu P, Liu T. Tai Ji Quan: An overview of its history, health benefits, and cultural value. J Sport Health Sci. 2014; 3(1):3-8. [DOI: 10.1016/j.jshs.2013.10.004]
54. Jakicic JM, Winters C, Lang W, Wing RR. Effects of intermittent exercise and use of home exercise equipment on adherence, weight loss, and fitness in overweight women: A randomized trial. JAMA. 1999; 282(16):1554-60. [DOI: 10.1001/jama.282.16.1554 ]
55. Zhu W. Should, and how can, exercise be done during a coronavirus outbreak? An interview with Dr. Jeffrey A. Woods. J Sport Health Sci. 2020; 9(2):105-7. [DOI: 10.1016/j.jshs.2020.01.005 ]
56. Mokhtarzade M, Ranjbar R, Majdinasab N, Patel D, Molanouri Shamsi M. Effect of aerobic interval training on serum IL-10, TNFα, and adipokines levels in women with multiple sclerosis: Possible relations with fatigue and quality of life. Endocrine. 2017; 57(2):262-71. [DOI: 10.1007/s12020-017-1337-y ]
57. Molanouri Shamsi M, Chekachak S, Soudi S, Gharakhanlou R, Quinn LS, Ranjbar K, et al. Effects of exercise training and supplementation with selenium nanoparticle on T-helper 1 and 2 and cytokine levels in tumor tissue of mice bearing the 4 T1 mammary carcinoma. Nutrition. 2019; 57:141-7. [DOI: 10.1016/j.nut.2018.05.022]
58. Friedrich MJ. Exercise may boost aging immune system. JAMA. 2008; 299(2):160-1. [DOI: 10.1001/jama.2007.56-a]
59. Wang J, Liu S, Li G, Xiao J. Exercise Regulates the Immune System. Adv Exp Med Biol. 2020; 1228:395-408. [DOI:10.1007/978-981-15-1792-1_27]
60. Molanouri Shamsi M, Amani Shalamzari S. [Exercise Training, Immune System, and Coronavirus (Persian)]. Sport Physiol. 2020; 12(46):17-40. https://www.sid.ir/en/journal/ViewPaper.aspx?ID=761859
61. Ahmadi Hekmatikar A, Haghshenas R, Mohammad Sadeghipor A. The effect of carbohydrate supplementation and pure water on interleukin 10, glucose and hematological indexes in male football players. Sport Physiol Manage Investig. 2019; 11(4):135-45. http://www.sportrc.ir/article_105715.html
62. Molanouri Shamsi M, Alinejad HA, Amani Shalamzari S, Aghayari A, Asghari Jafarabadi M, Talebi Badrabadi K. [Anti-inflammatory effects of a bout of circuit resistance exercise with moderateintensity in inactive obese males (Persian)]. JSSU. 2011; 19(5):598-609. http://jssu.ssu.ac.ir/article-1-1735-fa.html
63. Walsh NP, Gleeson M, Shephard RJ, Gleeson M, Woods JA, Bishop NC, et al. Position statement part one: Immune function and exercise. Exerc Immunol Rev. 2011; 17:6-63. [PMID]
64. Simpson RJ, Kunz H, Agha N, Graff R. Exercise and the regulation of immune functions. Prog Mol Biol Transl Sci. 2015; 135:355-80 [DOI:10.1016/bs.pmbts.2015.08.001]
65. Campbell JP, Turner JE. Debunking the myth of exercise-induced immune suppression: Redefining the impact of exercise on immunological health across the lifespan. Front Immunol. 2018; 9:648. [DOI:10.3389/fimmu.2018.00648]
66. Pedersen BK, Rohde T, Zacho M. Immunity in athletes. J Sports Med Phys Fitness. 1996; 36(4):236-45. [PMID]
67. Molanouri Shamsi M, Hassan ZM, Quinn LS, Gharakhanlou R, Baghersad L, Mahdavi M. Time course of IL-15 expression after acute resistance exercise in trained rats: Effect of diabetes and skeletal muscle phenotype. Endocrine. 2015; 49(2):396-403. [DOI:10.1007/s12020-014-0501-x]
68. Martin SA, Pence BD, Woods JA. Exercise and respiratory tract viral infections. Exerc Sport Sci Rev. 2009; 37(4):157-64. [DOI:10.1097/JES.0b013e3181b7b57b] [PMCID]
69. Phelan D, Kim JH, Chung EH. A game plan for the resumption of sport and exercise after coronavirus disease 2019 (COVID-19) infection. JAMA Cardiology. 2020; 5(10):1085-6. [DOI:10.1001/jamacardio.2020.2136]
70. Bangsbo J, Mohr M, Poulsen A, Perez-Gomez J, Krustrup P. Training and testing the elite athlete. J Exerc Sci Fit. 2006; 4(1):1-14. https://portal.findresearcher.sdu.dk/en/publications/training-and-testing-the-elite-athlete
71. Fox SM, Naughton JP, Haskell WL. Physical activity and the prevention of coronary heart disease. Ann Clin Res. 1971; 3(6):404-32. [PMID]
72. Garber CE, Blissmer B, Deschenes MR, Franklin BA, Lamonte MJ, Lee I-M, et al. American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: Guidance for prescribing exercise. Med Sci Sports Exerc. 2011; 43(7):1334-59. [DOI:10.1249/MSS.0b013e318213fefb]
73. Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001; 37(1):153-6. [DOI:10.1016/s0735-1097(00)01054-8] [PMID]
74. Khoramipour K, Basereh A, Hekmatikar AA, Castell L, Ruhee RT, Suzuki K. Physical activity and nutrition guidelines to help with the fight against COVID-19. J Sports Sci. 2021; 39(1):101-7. [DOI:10.1080/02640414.2020.1807089]
75. Vetrovsky T, Steffl M, Stastny P, Tufano JJ. The efficacy and safety of lower-limb plyometric training in older adults: A systematic review. Sports Med. 2019; 49(1):113-31. [DOI:10.1007/s40279-018-1018-x] [PMCID]
76. Chen P, Mao L, Nassis GP, Harmer P, Ainsworth BE, Li F. Wuhan coronavirus (2019-nCoV): The need to maintain regular physical activity while taking precautions. J Sport Health Sci. 2020; 9(2):103-4. [DOI:10.1016/j.jshs.2020.02.001] [PMCID]
77. Halabchi F,  Ahmadinejad Z,  Selk-Ghaffari M . Covid-19 epidemic: Exercise or not to exercise; That is the question. Asian J Sports Med. 2020; 11(1):e102630. [DOI:10.5812/asjsm.102630]
78. Toresdahl BG, Asif IM. Coronavirus disease 2019 (COVID-19): Considerations for the competitive athlete. Sports Health. 2020; 12(3):221-4. [DOI:10.1177/1941738120918876] [PMCID]
79. Pedersen BK, Saltin B. Exercise as medicine - evidence for prescribing exercise as therapy in 26 different chronic diseases. Scand J Med Sci Sports. 2015; 25(Suppl 3):1-72. [DOI:10.1111/sms.12581] [PMID]
80. Norouzi E, Hosseini FS, Vaezmosavi M, Gerber M, Pühse U, Brand S. Zumba dancing and aerobic exercise can improve working memory, motor function, and depressive symptoms in female patients with Fibromyalgia. Eur J Sport Sci. 2019; 20(7):981-91. [DOI:10.1080/17461391.2019.1683610]
81. Gabriel H, Kindermann W. The acute immune response to exercise: What does it mean? Int J Sports Med. 1997; 18(Suppl 1):S28-45. [DOI:10.1055/s-2007-972698] [PMID]
82. Radom-Aizik S. Immune response to exercise during growth. Pediatr Exerc Sci. 2017; 29(1):49-52. [DOI:10.1123/pes.2017-0003] [PMID]
83. Timmons BW, Cieslak T. Human natural killer cell subsets and acute exercise: A brief review. Exerc Immunol Rev. 2008; 14:8-23. [PMID]
84. Timmons BW. Exercise and immune function in children. Am J Lifestyle Med. 2007; 1(1):59-66. [DOI:10.1177/1559827606294851]
85. Boas SR, Danduran MJ, McColley SA, Beaman K, O’Gorman MR. Immune modulation following aerobic exercise in children with cystic fibrosis. Int J Sports Med. 2000; 21(04):294-301. [DOI:10.1055/s-2000-311]
86. Fallon K. Exercise in the time of COVID-19. Aust J Gen Pract. 2020; 49(Suppl 13):1-2. https://cardiologiadoexercicio.com.br/wp-content/uploads/2020/09/Exercicios-em-tempos-de-COVID-19.pdf
87. Ravalli S, Castrogiovanni P, Musumeci G. Exercise as medicine to be prescribed in osteoarthritis. World J Orthop. 2019; 10(7):262-7. [DOI: 10.5312/wjo.v10.i7.262] [PMCID]
88. Miles MP, Kraemer WJ, Grove DS, Leach SK, Dohi K, Bush JA, et al. Effects of resistance training on resting immune parameters in women. Eur J Appl Physiol. 2002; 87(6):506-8. [DOI:10.1007/s00421-002-0683-4]
89. Calle MC, Fernandez ML. Effects of resistance training on the inflammatory response. Nutr Res Pract. 2010; 4(4):259-69. [DOI:10.4162/nrp.2010.4.4.259] [PMCID]
90. Pedersen BK, Steensberg A, Keller P, Keller C, Fischer C, Hiscock N, et al. Muscle-derived interleukin-6: lipolytic, anti-inflammatory and immune regulatory effects. Pflugers Arc. 2003; 446(1):9-16. [DOI:10.1007/s00424-002-0981-z]
91. Suzuki K. Cytokine Response to Exercise and Its Modulation. Antioxidants (Basel). 2018; 7(1):17.[ DOI:10.3390/antiox7010017]
92. Stewart LK, Flynn MG, Campbell WW, Craig BA, Robinson JP, Timmerman KL, et al. The influence of exercise training on inflammatory cytokines and c-reactive protein. Med Sci Sports Exerc. 2007; 39(10):1714-9. [DOI:10.1249/mss.0b013e31811ece1c]
93. Raines C, Frosig T, Escobar KA, Cotter JA, Schick EE. Acute resistance exercise at varying volume loads does not enhance plasma interleukin-6. IJKSS. 2020; 8(1):37-42. http://www.journals.aiac.org.au/index.php/IJKSS/article/view/5855
94. Xiao C, Beitler JJ, Higgins KA, Chico CE, Withycombe JS, Zhu Y, et al. Pilot study of combined aerobic and resistance exercise on fatigue for patients with head and neck cancer: Inflammatory and epigenetic changes. Brain Behav Immun. 2020; 88:184-92. [DOI:10.1016/j.bbi.2020.04.044]
95. Scheffer DdL, Latini A. Exercise-induced immune system response: Anti-inflammatory status on peripheral and central organs. Biochim Biophys Acta Mol Basis Dis. 2020; 1866(10):165823. [DOI:10.1016/j.bbadis.2020.165823] [PMCID]
96. Dixit S. Can moderate intensity aerobic exercise be an effective and valuable therapy in preventing and controlling the pandemic of COVID-19? Med Hypotheses. 2020; 143:109854. [DOI:10.1016/j.mehy.2020.109854] [PMCID]
97. Highton PJ, White AEM, Nixon DGD, Wilkinson TJ, Neale J, Martin N, et al. Influence of acute moderate- to high-intensity aerobic exercise on markers of immune function and microparticles in renal transplant recipients. Am J Physiol Renal Physiol. 2020; 318(1):F76-85. [DOI: 10.1152/ajprenal.00332.2019]
98. Sitlinger A, Brander DM, Bartlett DB. Impact of exercise on the immune system and outcomes in hematologic malignancies. Blood Adv. 2020; 4(8):1801-11. [DOI:10.1182/bloodadvances.2019001317] [PMCID]
99. Nieman DC, Wentz LM. The compelling link between physical activity and the body’s defense system. J Sport Health Sci. 2019; 8(3):201-17. [DOI:10.1016/j.jshs.2018.09.009] [PMCID]
100. de Souza DC, Matos VAF, dos Santos VOA, Medeiros IF, Marinho CSR, Nascimento PRP, et al. Effects of high-intensity interval and moderate-intensity continuous exercise on inflammatory, leptin, iga, and lipid peroxidation responses in obese males. Front Physiol. 2018; 9:567. [DOI:10.3389/fphys.2018.00567] [PMCID]
101. Hajizadeh Maleki B, Tartibian B, Mooren FC, FitzGerald LZ, Krüger K, Chehrazi M, et al. Low-to-moderate intensity aerobic exercise training modulates irritable bowel syndrome through antioxidative and inflammatory mechanisms in women: Results of a randomized controlled trial. Cytokine. 2018; 102:18-25. [DOI:10.1016/j.cyto.2017.12.016]
102. Durrer C, Francois M, Neudorf H, Little JP. Acute high-intensity interval exercise reduces human monocyte Toll-like receptor 2 expression in type 2 diabetes. Am J Physiol Regul Integr Comp Physiol. 2017; 312(4):R529-38. [DOI:10.1152/ajpregu.00348.2016] [PMCID]
103. Szlezak AM, Szlezak SL, Keane J, Tajouri L, Minahan C. Establishing a dose-response relationship between acute resistance-exercise and the immune system: Protocol for a systematic review. Immunol Lett. 2016; 180:54-65. [DOI:10.1016/j.imlet.2016.10.010]
104. Dorneles GP, Haddad DO, Fagundes VO, Vargas BK, Kloecker A, Romão PRT, et al. High intensity interval exercise decreases IL-8 and enhances the immunomodulatory cytokine interleukin-10 in lean and overweight–obese individuals. Cytokine. 2016; 77:1-9. [DOI: 10.1016/j.cyto.2015.10.003]
105. Gomes EC, Florida-James G. Exercise and the Immune System. In: Esser C, editor. Environmental Influences on the Immune System. Vienna: Springer Vienna; 2016. https://www.springer.com/gp/book/9783709118887
106. Sarir H, Emdadifard G, Farhangfar H, TaheriChadorneshin H. Effect of vitamin E succinate on inflammatory cytokines induced by high-intensity interval training. J Res Med Sci. 2015; 20(12):1177-81. [DOI:10.4103/1735-1995.172986] [PMCID]
107. Zwetsloot KA, John CS, Lawrence MM, Battista RA, Shanely RA. High-intensity interval training induces a modest systemic inflammatory response in active, young men. J Inflamm Res. 2014; 7:9-17. [DOI:10.2147/JIR.S54721] [PMCID]
108. Gholamnezhad Z, Boskabady MH, Hosseini M, Sankian M, Khajavi Rad A. Evaluation of immune response after moderate and overtraining exercise in wistar rat. Iran J Basic Med Sci. 2014; 17(1):1-8. [PMCID]
109. Neves PRDS, Tenório TRDS, Lins TA, Muniz MTC, Pithon-Curi TC, Botero JP, et al. Acute effects of high- and low-intensity exercise bouts on leukocyte counts. J Exerc Sci Fit. 2015; 13(1):24-8. [DOI:10.1016/j.jesf.2014.11.003] [PMCID]
110. Zimmer P, Baumann FT, Bloch W, Schenk A, Koliamitra C, Jensen P, et al. Impact of exercise on pro inflammatory cytokine levels and epigenetic modulations of tumor-competitive lymphocytes in Non-Hodgkin-Lymphoma patients-randomized controlled trial. Eur J Haematol. 2014; 93(6):527-32. [DOI:10.1111/ejh.12395 ]
111. Child M, Leggate M, Gleeson M. Effects of two weeks of high-intensity interval training (HIIT) on monocyte TLR2 and TLR4 expression in high BMI sedentary men. Int J Exerc Sci. 2013; 6(1):81-90. https://digitalcommons.wku.edu/cgi/viewcontent.cgi?article=1485&context=ijes
112. Rahmati M, Khazani A, Gharakhanlou R, Movaheddin M, Manaheji H. [Chronic effects of moderate intensity endurance training on neuropathic pain symptoms in diabetic rats (Persian)]. Physiol Pharmacol. 2013; 16(4):435-45. http://irisweb.ir/files/site1/rds_journals/26/article-26-5876.pdf
113. Shirvani H, Ghahreman Tabrizi K, Sobhani V. [Effects of high intensity intermittent exercise on serum Immunoglobulin’s and Complement system response in youth soccer players (Persian)]. J Birjand Univ Med Sci. 2013; 20(3):233-43. http://journal.bums.ac.ir/article-1-1331-en.html
114. Navarro F, Bacurau AVN, Pereira GB, Araújo RC, Almeida SS, Moraes MR, et al. Moderate exercise increases the metabolism and immune function of lymphocytes in rats. Eur J Appl Physiol. 2013; 113(5):1343-52. [DOI: 10.1007/s00421-012-2554-y]
115. Wright BJ, Eddy PJ, Kent S. Work stress, immune, and inflammatory markers. In:  Bültmann U, Siegrist J, editors. Handbook of Socioeconomic Determinants of Occupational Health. Germany: Springer; 2020. https://www.amazon.com/Handbook-Disability-Health-Occupational-Sciences/dp/3030243354
116. Segerstrom SC, Miller GE. Psychological stress and the human immune system: A meta-analytic study of 30 years of inquiry. Psychol Bull. 2004; 130(4):601-30. [DOI:10.1037/0033-2909.130.4.601] [PMCID]
117. Felten SY, Felten DL. Neural-immune interactions. Prog Brain Res. 1994; 100:157-62. [PMID]
118. Cohen S, Williamson GM. Stress and infectious disease in humans. Psychol bull. 1991; 109(1):5-24. [DOI:10.1037/0033-2909.109.1.5]
119. Gouin JP. Chronic stress, immune dysregulation, and health. Am J Lifestyle Med. 2011; 5(6):476-85. [DOI:10.1177/1559827610395467]
120. Kennedy PJ, Cryan JF, Quigley EMM, Dinan TG, Clarke G. A sustained hypothalamic-pituitary-adrenal axis response to acute psychosocial stress in irritable bowel syndrome. Psychol Med. 2014; 44(14):3123-34. [DOI:10.1017/S003329171400052X]
121. Hightower LE, Santoro MG. Coronaviruses and stress: From cellular to global. Cell Stress Chaperones. 2020; 25(5):701-5. [DOI:10.1007/s12192-020-01155-4 ]
122. Kanneganti T-D, Dixit VD. Immunological complications of obesity. Nat immunol. 2012; 13(8):707-12. [DOI:10.1038/ni.2343]
123. de Heredia FP, Gómez-Martínez S, Marcos A. Obesity, inflammation and the immune system. Proc Nutr Soc. 2012; 71(2):332-8. [DOI:10.1017/S0029665112000092]
124. Guilherme A, Virbasius JV, Puri V, Czech MP. Adipocyte dysfunctions linking obesity to insulin resistance and type 2 diabetes. Nat Rev Mol Cell Biol. 2008; 9(5):367-77. [DOI:10.1038/nrm2391] [PMCID]
125. Feuerer M, Herrero L, Cipolletta D, Naaz A, Wong J, Nayer A, et al. Lean, but not obese, fat is enriched for a unique population of regulatory T cells that affect metabolic parameters. Nat Med. 2009; 15(8):930-9. [DOI:10.1038/nm.2002] [PMCID]
126. Deng J, Liu S, Zou L, Xu C, Geng B, Xu G. Lipolysis response to endoplasmic reticulum stress in adipose cells. J Biol Chem. 2012; 287(9):6240-9. [DOI: 10.1074/jbc.M111.299115] [PMCID]
127. Sartipy P, Loskutoff DJ. Monocyte chemoattractant protein 1 in obesity and insulin resistance. Proc Natl Acad Sci USA. 2003; 100(12):7265-70. [DOI: 10.1073/pnas.1133870100] [PMCID]
128. Lagathu C, Yvan-Charvet L, Bastard JP, Maachi M, Quignard-Boulangé A, Capeau J, et al. Long-term treatment with interleukin-1beta induces insulin resistance in murine and human adipocytes. Diabetologia. 2006; 49(9):2162-73. [DOI:10.1007/s00125-006-0335-z]
129. Weisberg SP, McCann D, Desai M, Rosenbaum M, Leibel RL, Ferrante Jr AW. Obesity is associated with macrophage accumulation in adipose tissue. J Clin Invest. 2003; 112(12):1796-808. [DOI:10.1172/JCI19246] [PMCID]
130. Karlsson EA, Sheridan PA, Beck MA. Diet-induced obesity in mice reduces the maintenance of influenza-specific CD8+ memory T cells. J Nutr. 2010; 140(9):1691-7. [DOI:10.3945/jn.110.123653] [PMCID]