### Concept of \"Long COVID\"  
The phrase \"Long COVID\" first appeared on social media to characterize the symptoms that persisted after the initial SARS-CoV-2 infection [17; 18]. Regardless of one's viral state, \"Long COVID\" is used as a broad name for a variety of symptoms that last for a long time after contracting the SARS-CoV-2 virus. The term \"post-COVID syndrome\" is also often used to describe Long COVID [19]. These symptoms may present in a variety of ways, reoccurring often or seldom [20]. These symptoms might include the recurrence of one or more acute COVID symptoms or the appearance of completely distinct symptoms. It is noteworthy that a considerable number of people with post-COVID syndrome test negative for PCR, showing microbiological recuperation. Post-COVID syndrome, put simply, is the interval of time between microbial recuperation and clinical recuperation [20; 21]. Patients with Long COVID often exhibit biochemical and radiological improvements. Depending on how long these symptoms last, Long COVID may be divided into two categories: \"post-acute COVID\", where symptoms last between 3 weeks and 12 weeks, and \"chronic COVID\", where symptoms last for longer than 12 weeks. Therefore, in a SARS-CoV-2-infected individual, the persistence of one or more symptoms, whether constantly or sporadically, whether they are distinct from or evoke one of acute COVID symptoms past the intended time frame of clinical recuperation is referred to as Long COVID [20; 21; 22]. A study conducted in Italy revealed that a significant proportion, specifically 87%, of individuals who had recuperated and were discharged from hospitals exhibited the persistence of at least one lingering symptom even after a span of 60 days [23]. Within this group, it was observed that 32% endured one or two lingering symptoms, while a substantial 55% reported the presence of three or more. Notably, these lingering symptoms did not include fever or signs indicative of acute illness. Instead, the most commonly reported issues included fatigue (53.1%), a decline in overall quality of life (44.1%), difficulty breath ing (43.4%), joint pain (27.3%), and chest discomfort (21.7%). Additionally, individuals mentioned experiencing symptoms like cough, skin rashes, palpitations, headaches, diarrhea, and a sensation akin to \"pins and needles\". These persistent symptoms significantly hindered the ability of these individuals to perform activities of daily living (ADLs) [24]. Being able to perform ADLs on a routine basis is a crucial component of independent living and also impacts one's quality of life [25; 26]. So, the persistence of such symptoms had a significant impact on the elderly population worldwide, who, in addition to being the diversity group that was most affected by COVID-19, were also among the diversity groups that were most affected by Long COVID [27]. Moreover, the elderly population, as well as patients from other age groups grappling with these enduring symptoms, also reported mental health challenges, including anxiety, depression, and post-traumatic stress disorder. Another study noted that individuals who had been discharged from the hospital after battling COVID-19 continued to struggle with breathlessness and overwhelming fatigue even three months post-discharge [28]. Notably, the prevalence of these residual symptoms varies depending on the context of treatment. Approximately 35% of individuals treated for COVID-19 on an outpatient basis reported lingering symptoms, while the percentage significantly rose to around 87% among cohorts of hospitalized patients [23; 29]. According to several recent studies, the frequently observed symptoms of Long COVID include fatigue, headaches, attention-related issues, hair loss, and difficulty breathing [30; 31; 32; 33]. Recent research works in this field have indicated that rehabilitation could be effective in addressing certain instances of Long COVID. In the realm of rehabilitation, patients are advised to engage in gentle aerobic exercises adjusted to their personal capabilities.