In December 2019, the World Health Organization (WHO) officially reported cases of pneumonia with no apparent cause, in the province of Hubei in China, the new disease caused by a type of coronavirus was designated with COVID-19 (1). COVID-19 quickly crossed borders, infecting people around the world, and was considered a pandemic in early March (2). Currently there are officially 5,438,837 confirmed cases and 340,585 deaths by the new virus. At the moment, Brazil stills in an upward curve of contamination, in May 24, 2020 there were 347,398 cases of infected with 22,013 numbers of deaths (https://covid.saude.gov.br).

Widespread outbreaks of infectious diseases, such as COVID-19, are associated with emotional and psychological distress and symptoms of mental disorders, with a higher prevalence of anxiety, depression, and stress (3–7). The number of people affected by these symptoms tends to be higher than the number of people affected by the infection (8, 9). Limited knowledge about COVID-19, lack of update on COVID-19, duration of home confinement, poor physical health and physical symptoms, lack of access to healthcare, lack of activity, uncertainty regarding the economic scenario and health systems can increase anxiety and depression (3, 6, 10, 11). In addition, social isolation—working and studying at home, having dependent children, decreased physical contact with other people—can be a significant psychological stressor (12, 13) and cause negative lifestyle changes such as poor diet and physical inactivity (14).

Physical exercise (PE) has been associated with improved psychological outcomes (15); and its neurobiological effects seem to influence several neural mechanisms related to depressive and anxiety disorders (16, 17). The absence or reduction of PE has been associated with an increased risk of mental disorders such as anxiety and depression (18–20). Although there is not yet an ideal dose of exercise for this type of diseases, there is evidence demonstrating that any exercise is better than none on mental disorders (15, 20, 21). Studies show that the regular practice of PE can be compared to pharmacological measures for the treatment of mental disorders such as depression (22, 23).

However, in the midst of the global public health crisis scenario, little is known about the relationship between PE and the attenuation of symptoms of mental disorderscaused by the current pandemic. Morover, it would be important to know if physcial activity habits would be related to markers of stress, anxiety, and depression. In view of the above, the objective of this study was to evaluate the levels of anxiety, depression, and stress associated with the practice of PE during COVID-19 outbreak.

A recent scientometric analysis found that the most common research topics include emergency care and surgical, viral pathogenesis, and global responses in the COVID-19 pandemic but there is a lack of research on PE (27). Our results showed an increase of 67.14% in the number of people who did not perform PE during the COVID-19 pandemic. Women had higher scores of anxiety, depression, and stress when compared to men. Our analysis showed that thosewho did not practice PE showed higher values in all subscales evaluated (anxiety, depression, and stress). After binary logistic regression, the lack of PE practice was associated with higher values of anxiety, depression, and stress in both men and women.

Our results showed that individuals who performed PE during coronavirus outbreak presented lower levels of anxiety, stress and depression. When considering both sexes, those who did not perform PE had a 118% higher risk of presenting symptoms of anxiety, 152% more chance of having values of depression above normal and 75.1% higher risk of having symptoms of stress. Women who did not perform PE were 134% more likely to have high anxiety scores, 136% more likely to have depressive symptoms and 66% more likely to show high levels of stress. As for men, those who were not involved with PE were 192, 304, and 224% more likely to have high levels of anxiety, depression, and stress, respectively, as shown in Table 5.

Our results are in agreement with previous studies. Fluetsch et al. (28) evaluated the “The 2015 Behavioral Risk Factor Surveillance System” and found an inverse relationship between PE and mental health for those who reported being insufficiently active. Teychenne et al. (29) reported that sedentary behavior was associated with increased risk of anxiety. A meta-analysis documented that PE interventions significantly improved depressive symptoms among healthy adults (30). Moreover, it has been shown that PE have the potential to decrease the self-reported days of mental health problems due to anxiety, depression, and stress (28). Schuch et al. (31), when performing a meta-analysis with prospective studies (at least 1 year of follow-up), showed that higher levels of self-reported PE are associated with a lower risk of anxiety symptoms and anxiety disorders when compared to lower levels of PE.

The relationship between PE and mental health problems seems to be bidirectional. Exercise reduce the risk of anxiety and/or depression symptoms, but these symptoms may also lead the individual perform PE. Da Silva et al. (32), reported that regular PE was associated with a lower probability of depressive symptoms; but in the inverse analysis, participants with symptoms of anxiety and depression were more likely to not reach the recommended levels of PE. However, there are possible mechanisms that might explain the influence of PE on mood. These mechanisms though might involve the release of endorphins (33), thermogensis (34), the activation of the mTOR axis in specific brain regions (35) and neurotransmitters such as dopamine and serotonin (36, 37).

In the current scenario, measures aiming to control covid-19 dissemination require social isolation and restrictions that might agravate mood symptoms. However, the present results suggest that PE may decrease the risk of depression, anxiety, and stress. Therefore, it might be advisable to recommend the performance of PE, obviously respecting safety recommendations as part of the behavior therapy (38) and health education (39) during the COVID-19 pandemic.

The WHO recommends 150 min of PE for asymptomatic people, which can be distributed throughout the week, and for those people with comorbidities who do not present symptoms the recommendation is to continue with active habits (40) From a practical standpoint, PE can be performed with numerous possibilities. It is possible to adapt materials, use body weight exercises, elastic bands, exercise with no external loads, calisthenics and others (41–49).

The study has some important limitations. We opted to perform a simple analysis of PE habits (yes or no question). Whist this facilited response, it does not precisely define different levels, so we cannot stablish a dose response relation. Another important limitation is that the mode of delivery (electronic) leaded mostly younger adults that have access to internet to respond; therefore, it might not reflect the situation of groups with different socioechonomical and age status. It might not reflect the situation of groups with different socioechonomical and age status. This study did not explore the use of face mask as preventive measures which was found to be associated with lower prevalence of depression (7) but cannot be used during PE.

Based on the present results, it is possible to note a reduction in regular PE during social isolation. Moreover, people who was not involved with PE during the COVID-19 pandemic had higher anxiety, depression, and stress scores. Based on this, it seems important to advise people to continue PE, following all the recommendations of preventive measures of the pertinent health organizations.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

This study involved human participants and was reviewed and approved by the Research Ethics Committee linked to the Center for Excellence in Teaching, Research and Projects Leide das Neves Ferreira of the National Health Council. The patients/participants provided their written informed consent to participate in this study.

LRBS: concept and study design, collected and analyzed data, wrote, reviewed, and edited the manuscript. CS and CO: collected data, wrote, reviewed, and edited the manuscript. PS, JO, LFMS, and CP: collected data and edited the manuscript. PG and AR: contributed with data analysis, reviewed, and edited the manuscript. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.