Journal of Exercise & Organ Cross Talk

Abstract While COVID-19 vaccines have reduced the prevalence of new viral strains, they are associated with side effects, including optic neuritis (ON). Developing effective management strategies, particularly non-pharmacological interventions, may improve outcomes for affected patients. This case study evaluated the effects of 8 weeks of yoga therapy in two male patients, aged 58 and 43, who developed ON two weeks post-vaccination. Assessments included visual field and color perception tests, the Balance Error Scoring System (BESS), the National Eye Institute Visual Function Questionnaire (NEI VFQ-25), and the Beck Depression Inventory II (BDI-II). Results from the yoga therapy patient were compared to a control case. The yoga therapy patient showed marked improvements: visual field enhancements of 48% (left eye) and 42% (right eye), a 53% increase in color perception, and a 31-turn improvement in the 6-Minute Walk Test. BESS errors reduced, heart rate recovery improved by 22 beats per minute, NEI VFQ-25 scores rose, and BDI-II scores declined. The control patient experienced no changes. Yoga therapy may complement pharmacological treatments for ON, offering benefits through anti-inflammatory effects, HPA axis modulation, and neuroprotective mechanisms that support remyelination. The integration of exercise and medication, termed "MedXercise," shows potential for managing vaccine-related side effects. Further research should explore varied exercise regimens to confirm these findings.

Abstract Research indicates that a sedentary lifestyle significantly contributes to the development of post-COVID syndrome (PCS), characterized by persistent symptoms following acute COVID-19 infection. Engaging in regular physical activity is essential not only for mitigating these risks but also for enhancing recovery from COVID-19. Studies have shown that individuals who maintained high levels of PA before and after infection experienced fewer and less severe symptoms associated with PCS. Specifically, exercise training has been identified as a critical intervention for improving muscle function and modulating adipokine levels—signaling proteins released by adipose tissue that play a role in inflammation and metabolic regulation. Given the complex pathogenesis of PCS, which involves various physiological and psychological factors, it is imperative to incorporate structured exercise regimens into rehabilitation programs for affected individuals. Aerobic endurance training has demonstrated significant benefits in improving exercise capacity, reducing fatigue, and enhancing overall quality of life in PCS patients. Furthermore, high levels of PA are associated with improved immune function and lower rates of reinfection. In conclusion, promoting mandatory physical activity during and after pandemic conditions is vital for reducing the burden of post-COVID syndrome and enhancing public health outcomes. This review underscores the necessity for healthcare providers to advocate for exercise as a primary strategy in managing post-COVID symptoms and preventing future chronic diseases linked to sedentary behavior during different pandemics.

Abstract The immune system is one of the main defenders of human health. The immune system can fight off viruses in the body and kill them. Therefore, keeping the components of the immune system healthy is very important. With age, the immune system ages, and its function decreases. This decline in immune function can easily lead to viral infections in the elderly. Evidence is accumulated that the best solution to maintain and enhance the immune system in the elderly is physical activity. Regular physical activity can lead to healthy aging of the immune system. Therefore, in this review study, we have discussed the changes in the immune system during aging and physical activity suggestions for healthy aging of the immune system. Finally, future research needs are reported.

Abstract The prevalence of obesity among children and adolescents is one of the most serious public health challenges of the 21st century. Implementing social distancing policy measures, such as the stay-at-home order, to control the spread of coronavirus disease 2019 (COVID-19) not only has affected lifestyles and weights in children but has also created an obesity-inducing environment, leading to modifications in the patterns of interactions between this age group and their surrounding environment. Therefore, the COVID-19 pandemic has been effective in childhood obesity and its prevalence rate may continue increasing. This narrative review aimed to synthesize evidence from global studies on physical inactivity, and obesity among children and adolescents during COVID-19, and then prescribe an evidence-based home exercise guideline for this age group. The study findings revealed that the COVID-19 restrictions have drastically multiplied physical inactivity and obesity in children. It has been further established that childhood obesity leads to numerous chronic diseases, including diabetes mellitus, cardiovascular diseases (CVDs), psychosomatic disorders, lung diseases, and other metabolic problems in childhood and even as children grow up. Physical activity/exercise at home during and after COVID-19 has been correspondingly demonstrated to mitigate the problems associated with obesity. A wide range of resistance, aerobic, balance, flexibility and other types of exercises have been accordingly shown to protect against the negative effects of the pandemic on child health. Hence, efforts to facilitate such exercises are suggested to continue and be scaled up to prevent childhood obesity and relevant diseases during and after this unusual period.

Abstract Dear Editor-in-Chief
In recent years, exercise has been called an ‘amazing’ medicine and a ‘miracle’ cure. Scientific research shows that regular exercise is effective in preventing and treating many common diseases, including type 2 diabetes, dementia, depression, heart disease, some cancers, and other common diseases (Fang et al., 2022). In fact, exercise in a specific dose and formula is prescribed for each patient who is diagnosed with the disease. The prescription should be very clear in terms of modality, intensity, frequency, and duration.
In this regard, the American College of Sports Medicine (ACSM) has launched the "Exercise is Medicine" project to recognize the myriad health benefits of exercise. These include reducing the incidence of a number of different cancers, lowering the risk of excessive weight gain (along with related health problems as well as diabetes), and improving cardiovascular health (as well as reducing the risk of high blood pressure in addition to heart stroke) (Ghardashi-Afousi et al., 2018).
The acute effect of exercise has been shown to lead to a transient decrease in triglyceride levels, an increase in HDL cholesterol levels, a decrease in blood pressure, a decrease in insulin resistance, and an improvement in glucose control. Regular exercise increases blood flow and oxygen to the brain which improves memory and mental function. It also increases the production of a number of hormones that stimulate the growth of brain cells (Ueno-Pardi et al., 2022).
In addition, some literature describes exercise even better than medicine. For example, a review of more than 300 randomized controlled trials found that exercise was as effective as drugs at risk for heart disease and diabetes, and more effective than post-stroke rehabilitation drugs (Naci & Ioannidis, 2013).
It has previously been suggested that vaccinating children with exercise can control the obesity epidemic in them. Recently, in the coronavirus outbreak, exercise has been referred to as a vaccine or vaccine adjuvant (Naci & Ioannidis, 2013). A recent study in the British Journal of Sports Medicine (BJSM) suggests that routine activities may protect people with COVID-19 from serious illness.
Evidence suggests that exercise and obesity are involved in the pathogenesis of COVID-19 disease and vaccine efficacy. Regular exercise has been shown to exert immune regulatory effects, control viral gateway, modulate inflammation, stimulate NO production pathways, and control oxidative stress. Adaptation to ordinary exercise seems to affect immune function, particularly innate and adaptive immunity, and ameliorate humoral immunity with enhanced vaccination responses. Exercise may at least partially reduce the detrimental effect of SARS-CoV-2 binding to the ECA2 receptor. Exercise training can activate anti-inflammatory signaling pathways (Shirvani & Rostamkhani, 2020). Today, COVID-19 vaccination has shown that individuals who exercise continuously and regularly may develop higher antibody titers to the SARS-CoV-2 strain contained in the vaccine compared to individuals who do not exercise (Hallam et al., 2022).
On the other hand, understanding how obesity and adiposity affect immunity and more specifically the production and function of antibodies is of great importance (Malavazos et al., 2020). Numerous studies have shown the effect of obesity on antibody properties. For example, adaptive immune responses to influenza virus are impaired during obesity, innate and adaptive immune responses to influenza are delayed in obese patients, and obesity was suggested to decline influenza antibody titers following influenza vaccination and reduce vaccine efficacy with poor vaccine immunization. In the same manner, lower COVID-19 mRNA vaccine-induced antibody titers have been related to central obesity and severe acute respiratory syndrome (Ghanemi et al., 2021).     
In general, recent research on the Covid-19 epidemic has shown that exercise is not only a wonderful medicine in the prevention and treatment of many diseases, but also regular exercise can act as an adjunct vaccine. Therefore, prescribing exercise will always help promote community health and is completely in line with the P4 medicine approach (predictive, preventative, personalized, and participatory).

Abstract Dear Editor-in-Chief
The world has recently experienced one of the hardest pandemics, COVID-19. Clinical signs of this disease include fever, dry cough, and diarrhea, or different symptoms that lead to acute respiratory distress syndrome with a further increase in the severity of the disease. Although the first observations of this disease are the involvement of symptoms and respiratory and heart injuries, various studies have also shown the nerve damage caused by this disease. Common neurological symptoms include headache, dizziness, anosmia, seizures, or paralysis. The elderly and critically ill are in the high-risk group and have shown severe neurological symptoms after COVID-19. Apart from COVID-19-induced cellular and neurological damage, this disease has a profound effect on the mental health of people around the world. Increasing the duration of this disease and staying at home causes social and economic problems and as a result mental health problems (Verma et al., 2020). Neurological and mental illnesses are very common all over the world.
Psychological resilience was an important issue during COVID-19 epidemic. In other words, during an epidemic, mental health of people should be consider and cheeked, and entertainment programs should be prevented from causing psychological damage. Research during the COVID-19 epidemic found that because of the psychological pressures to increase psychological resilience, people tended to be more exposed to the outdoors, exercise more, receive more social support from family, friends and important people, sleep better, and pray more, that these factors were effective in mitigating psychological trauma. In most studies, spiritual health affects mental health, because repeated prayers and worships have been more independently associated with psychological resilience (Killgore et al., 2020). In other words, those who actively participate in these spiritual activities and strengthen their relationship with God are found to have the most psychological resilience to the mental health challenges imposed by COVID-19. In addition, the effects of exercise at the cellular level can help improve memory and psyche and be effective in improving psychological resilience. To date, no studies have been performed on secretions due to muscle contraction and its effect on the brain and psychological function, and psychological resilience especially to control the psychological damage caused by an epidemic.
Exercise has many beneficial effects on brain health and helps reduce the risks of dementia, depression, and stress, and is involved in restoring and maintaining cognitive function and metabolic control. The fact that exercise is sensed by the brain suggests that environmental factors induced by the muscle allow a direct link between muscle function and the brain. Muscles secrete myokines that help regulate hippocampal function. Evidence is accumulating that myokine cathepsin B crosses the blood-brain barrier to increase brain-derived neurotrophic factor production, resulting in neurogenesis, memory, and learning. In addition, the muscle tissue itself can affect the central nervous system, memory, and psyche in form of endocrine by increasing BDNF expression. Exercise also increases the expression of the neurogenic gene FNDC5 (which encodes myogenic FNDC5-dependent PGC1α), which in turn can help increase levels of brain-derived neurotrophic factor (Pedersen, 2019).
Serum levels of myokine, IL-6, increase with exercise and may have beneficial effects on the central nervous system. Exercise also increases PGC1α-dependent muscle expression and the enzymes kynurenine aminotransferase, which beneficially alters the balance between the neurotoxic kynurenine and the neuroprotective Kynurenic acid, thereby reducing depressive symptoms. Signaling myokine and other muscle factors and exercise-induced hepatokines and adipokines play a role in the beneficial effects of exercise on neurogenesis, cognitive function, appetite, and metabolism, thus supporting the existence of a muscle-brain endocrine axis. Also, it can affect psychological resilience which needs more studies.

Abstract The COVID-19 epidemic has caused lifestyle changes in people from all walks of life and has become a global threat to the health and well-being of all countries of the world. Considering changes caused by the prevalence of the disease and quarantine conditions, the increased likelihood of the prevalence of overweight and obesity in people is among these threats. On the other hand, patients with overweight and obesity, and consequently, non-alcoholic fatty liver disease (NAFLD) have a weaker immune system than other people with ideal weight, and as a result, are more likely to develop COVID-19. As there is currently no definitive treatment for COVID-19 and NAFLD, and because people with NAFLD are more likely to develop COVID-19 based on the research in this area, paying attention to this important issue is thus necessary. Considering a regular physical activity program and having a balanced diet are among the essential strategies and may help prevent NAFLD, and consequently, COVID-19. However, given the novelty of COVID-19 pathogen and the ambiguity of the exact cause of why people get NAFLD, further research is needed to be done on the type of effective diet, as well as the type, intensity, and volume of exercise for these people. This study aimed to summarize the available evidence on the pathology and epidemiology of NAFLDs and COVID-19, as well as the effect of NAFLD on COVID-19 in people. Given the existing risks, the nutrition and exercise strategies were investigated in this regard.
 

Abstract Dear Editor-in-Chief
Coronaviruses are a very large family of viruses that are phenotypically and genetically diverse and are common in humans and animals. The Prevalence of Coronavirus disease 2019 (COVID-19) began in Wuhan, China. As of 17 March 2020, extensive human-to-human transmission mainly occurs via the respiratory particles of the infected person.  Among COVID-19 cases, it seems that new pandemic complications are already well-defined in obese and overweight people with body mass indexes (BMI) over 25 kg/m2 or even higher that contribute to increased risk of SARS-CoV-2 infection. The higher BMI in COVID-19 patients, the higher risk of medical complications, hospitalization in the intensive care unit (ICU), and invasive mechanical ventilation (IMV) (Földi et al., 2020). However, BMI does not show the distribution of body fat, and therefore research results cannot show the effect of excess fat in different parts of the body on the severity of COVID-19. In confirmation of this finding, it can be said that although the ratio of total body fat in women is higher than men on average, the incidence of COVID-19 is higher in men (Simonnet et al., 2020).
The possible critical mechanism by which adipose tissue accumulation increases the risk of COVID-19 in patients is unknown. However, fatty tissue may serve as a reservoir for viral production that might contribute to the increased risk from COVID-19 for patients with obesity. It is suggested that fatty tissue is targeted by SARS-CoV-2. The mechanism by which SARS-CoV-2 enters cells is not fully elucidated. But apart from a direct fusion of the virus with the plasma membrane, it appears that various types of endocytosis might be involved in this process. These lipid membrane trafficking events include clathrin-mediated endocytosis, caveolin- mediated involved in muscle hypertrophy and strength. In this regard, OCN-deficient mice have been shown to have lower muscle mass; inversely, improved muscle mass was found in older mice with ucOCN administrations. Recent data has figured out a novel mechanism of bone-muscle crosstalk in relation to OCN and IL6 signaling (Kirk et al., 2020).
Endocytosis, macropinocytosis, and phagocytosis. Caveolin-mediated endocytosis is especially interesting to study as caveolae are abundant in fat cells, caveolins participate in fatty tissue function because caveolin was shown to interact with various viral proteins. In addition, the increased number of fat cells would increase the pool of infection susceptible cells. Fatty tissue contains not only fat cells but cells of stromal vascular fraction among which adipocyte precursors and macrophages. These cells also express ACE2 and display a potential target of SARS-Cov-2 infection and thus may contribute to increased inflammatory status (Dugail, Amri, & Vitale, 2020). Another possibility is that fatty tissue droplets could provide a platform for virus replication and production. Concerning the hypothesis that fatty tissue is an infection place for the SARS-CoV-2 virus, it has not yet been established if viral loads are proportional to fatty tissue mass in patients. The ACE2 activity leading to increased levels of angiotensin II and so increased inflammation and lung damage. It seems that fat cells play a substantial role in viral infection and the viral life cycle. Adipose tissue is directly involved in contact with the viral membrane of the host cell. For example, fats are critical to the formation and function of the viral replication complex and can provide some of the energy required for viral replication. In addition, specific fats are needed for the formation of double-membrane vesicles for viral genome amplification and the production of viral particles. Viral internalization can occur with endocytosis and viral release from cells. It is possible that fat availability and fats metabolism modifications occurring in an obese patient also contribute to improving several stages of the virus's life cycle and severity of the disease (Dugail et al., 2020).
In this regard, any approach should consider reducing the costs of intensive care units to reduce the mortality of patients. Especially with concerning increase their number and people at higher risk in obese people. Moderate-intensity exercise can directly boost the immune system, antioxidant defenses, and anti-inflammatory responses Adipose tissue molecular adaptation always was considered as one of the mechanisms for the anti-inflammatory effects of physical exercise. Aerobic exercise is a physical activity that is moderate-intensity and does not put much pressure on the body. Regular exercise has been shown to improve infection, antibacterial and antiviral immunity, reduce inflammation, and delay immune aging (Campbell & Turner, 2018). Following the moderate-intensity physical activity, an increase in the number of neutrophils and natural killer (NK) cells is detected, and salivary IgA concentrations increase (Brolinson & Elliott, 2007). During physical exercise, rapid and general mobilization of NK cells into the bloodstream is induced by adrenergic B signaling and catecholamines. It is suggested that mobilized NK cells are affected by muscle-derived myokines, exercise-related hyperthermia, and coronary arteries, which are affected by regulation, redistribution, and activation of mobilized NK cells (Brolinson & Elliott, 2007). Moreover, adipocytes play a critical role in NK cell activations. Adipose tissue may respond to the activation of NK cells during exercise in a cross-talk with the immune system.
Moderate exercise was exercise is one of the mechanisms in NK cell activation following physical exercise.  The results show a 20 to 30 percent reduction in upper respiratory tract infections in people who do moderate-intensity of physical activity in their daily lives (Brolinson & Elliott, 2007). Therefore, it can be said that moderate-intensity training can be an effective way to boosting the immune system. Possible cross-talk between fat and immune tissues was approved in some other studies. It is suggested that some exercise factors such as IL-6 and Hsp70 can be effective in the possible cross-talk between the immune system and fat tissue. Molecular and structural changes in adipose tissue following physical exercise can be effective in improving immune responses.
Fatty tissue is probably targeted by the SARS-CoV-2 virus, which causes adipose tissue dysfunction. Accumulation of fat tissue also serves as a platform for replication and production of virus. Based on the evidence, it seems that exercise activities, especially combined exercise training, reduce fat mass in obese or overweight people, reduce the risk of COVID-19, as well as the risk of severity and side effects in patients. Possible cross-talks between the immune system and adipose tissue could be one of the possible mechanisms in boosting immune responses against the virus.