IJCS | Volume 33, Nº4, July and August 2020

402 done at home as therapy to fight against the physical and mental consequences of Covid-19 quarantine. The authors suggested a multicomponent exercise program, including aerobic, resistance, balance, coordination, and mobility training exercises both in outdoor environments and in community homes. In addition, a recent point of view 11 suggested the maintenance of physical activity in open environments or indoors during the period of the COVID-19 pandemic. The authors also called attention to the reduction of sedentary behavior, that is, the time we spend sitting, lying down, or reclining, except for the hours of sleep during the day. Position of theAmerican College of SportsMedicine In a recent position of the American College of Sports Medicine, 5 it was suggested the practice of outdoor and indoor physical activities, which could positively modulate the immune function. The outdoor activities, suggested by this entity, were walking or running around the neighborhood, using a local park to be active, taking a bike ride in nature, and also doing gardening and lawn work, and playing active games with the family. The authors recommended that people should always avoid crowded spaces and wash their hands when get home. As indoor physical activities, the American College of Sports Medicine suggested to put on some music and walk quickly around the house, go up down the stairs 2-3 times a day, dance, jump rope, follow an exercise video, and use cardio machines at home. Legal determinations in European countries during the pandemic Inrecent legaldeterminationspublishedincountrieslike the United Kingdom and France, the practice of physical activities in open environments was recognizedas an essential activity during the quarantine period. In case of the United Kingdom, 6 people were instructed to leave home for one of the four reasons: purchases of basic necessities, such as food andmedicines, which should be as infrequently as possible; practicing one type of exercise a day, for example, running, walking or cycling (alone or with members of your family); any medical need; to help a vulnerable person; and go to work, but only when it cannot be done at home. With regard to France, 7 circulation is allowed upon presentation of a completed, dated and signed form, justifying the reason for leaving. Among the permitted activities, physical activity was considered essential, as explained in the document: short journeys, limited to one hour per day andwithin a radius of 1 kilometer from home, related either to individual's physical activity (excluding collective sporting practices or involving any proximity to other people), either to a walk with people who live in the same household, or to fill the needs of pets. Importance of physical activity and its benefits for the cardiovascular, metabolic, and immune systems and mental health The benefits of physical activity to cardiovascular and metabolic health have been widely and long reported in the literature. Physical activity has an inverse association with blood pressure levels, 12 diabetes, 13 lipid changes, 14 risk of coronary artery disease, 15 and risk of cardiovascular events, 16 acting as an important protective factor for different cardiometabolic disorders. In addition, more recently, the importance of reducing sedentary behavior has also been discussed as an important approach to maximize the benefits of physical activity in preventing cardiometabolic disorders. 17 Regarding the immune system, physical activity, especially at moderate intensity and duration, can favor immune responses and improve resistance of the body. On the other hand, high-intensity and prolonged exercise can cause immunosuppression and therefore should be avoided during the COVID-19 pandemic. 9 A recent publication 18 by Italian researchers presents lessons learned from studies on influenza and physical activity in obese patients and suggests that the findings may be considered for COVID-19. The authors emphasize the positive effects on immunomodulation provided by the practice of light- to moderate-intensity physical exercise. 18 In the same line of reasoning, in a study carried out in the USA, it was observed that physical exercise acts as a preventive agent against viral influenza infection, both in obese and non-obese rats. 19 As for mental health, several studies have shown that the practice of physical activity can bring important benefits for the prevention of depression, 10 anxiety, Burnout syndrome and perceived stress. 20 Thus, physical activity becomes an important ally for the management of these health problems that affect the population, especially during the COVID-19 pandemic. 4 Pitanga et al. Physical Activity and COVID-19 Int J Cardiovasc Sci. 2020; 33(4):401-403 Viewpoint