Nutritional and physical activity issues in frailty syndrome during the COVID-19 pandemic.

'Frailty' has been described as 'a state of increased vulnerability of the individual caused by an impairment of homeostasis as a result of endogenous or exogenous stress'. Frail individuals are depicted by a dramatic change in health status following an apparently minor insult and a higher risk of adverse health-related outcomes such as osteoporosis and sarcopenia, falls and disability, and fragility fractures. Frailty is a condition of increasing importance due to the global ageing of the population during the last decades. Central to the pathophysiology of frailty is a mechanism that is partially independent of ageing, but most likely evolves with ageing: the cumulative level of molecular and cellular damage in every subject. Furthermore, an uncorrected nutrition and a sedentary behaviour play a pivotal role in worsening the syndrome. In January 2020, a cluster of a genus of the family Coronaviridae was isolated as the pathogen of the new coronavirus disease (COVID-19). Since then, this infection has spread worldwide causing one of the most dramatic pandemics of the modern era, with more than 500 million confirmed cases all over the world. The clinical spectrum of SARS-CoV-2 severity ranges from asymptomatic conditions to mild symptoms, such as fever, cough, ageusia, anosmia and asthenia, up to most severe conditions, such as acute respiratory distress syndrome (ARDS) and multi-organ failure leading to death. Primary evidence revealed that the elderly frail subjects were more susceptible to the disease in its most intense form and were at greater risk of developing severe COVID-19. Factors contributing to the severity of COVID-19, and the higher mortality rate, are a poor immune system activity and long-standing inflammatory status of the frail subjects compared with the general population. Further recent research also suggested a potential role of sedentary behaviour, metabolic chronic disorders linked to it and uncorrected nutritional status. Thus, the aim of this review was to evaluate the different studies and evidence related to COVID-19 pandemic, both nutritional status and physical activity, and, also, to provide further information on the correct nutritional approach in this peculiar pathological condition.