Diminished volumes of habitual physical activity and increased sedentary levels have been observed as a result of COVID-19 home-confinement. Consequences of inactivity, including a higher mortality rate and poorer general health and fitness, have been reported. This systematic review aimed to provide practical recommendations for maintaining active lifestyles during pandemics. In May 2020, two electronic databases (PubMed; Web of Science) were used to search for relevant studies. A total of 1206 records were screened by two researchers. Thirty-one relevant studies were included in this systematic review, in which the methodological quality was assessed. With regard to six studies, which explicitly dealt with physical activity during COVID-19, the evidence level is classified by three articles to level II, and in the other three to level VI. Regarding the physical activity recommendations in these papers, three of them were classified to a medium, and the same number to a weak evidence base. Of the 25 papers which refer to other pandemics and/or isolation situations, one was classified to evidence level I, four were ranged to level II, three to level III, one to level V, and the others to level VI. This systematic review revealed that reduced physical activity levels are of serious concern during home confinement in pandemic times. The recommendations provided by many international organizations to maintain active lifestyles during these times mainly target the general population, with less consideration for vulnerable populations (e.g., older adults, people with health issues). Therefore, personalized and supervised physical activity programs are urgently needed, with the option to group-play physical activity programs (e.g., exergames). These can be assisted, delivered, and disseminated worldwide through information and communication technology solutions. If it is permitted and safe, being active outside in daylight is advised, with an effort level of mild to moderate using the rating of perceived exertion scale. Relaxation techniques should be integrated into the daily routine to reduce stress levels. On the evidence base and levels of the included articles in this review, the results need to be interpreted with caution. Given that policies are different across regions and countries, further research is needed to categorize recommendations according to different social-distancing scenarios.
Keywords: COVID-19; pandemic; physical activity; quarantine; recommendations; social isolation.