Physical activity during the coronavirus disease-2019 global pandemic

Nearly a century ago, the 1918 influenza pandemic was regarded as the most severe pandemic in recent history.¹ The virus, known as H1N1, infected 500 million persons worldwide and claimed an estimated 50 million lives. The pandemic lasted nearly 2 years with sporadic activity characterized by 3 waves of occurrence. Nearly 100 years later, in January 2020, we found ourselves in the midst of another global pandemic, the novel coronavirus (coronavirus disease-2019, COVID-19).² Within 5 months of outbreak, COVID-19 has infected over 6 million persons worldwide with over 380,000 confirmed deaths.³ While nearly every region of the world has experienced the virus, European and North and South American countries are among the most impacted countries with the greatest burden of COVID-19 in terms of the incidence and mortality.⁴ Among the most vulnerable populations, older adults and persons with serious underlying medical conditions or compromised immune systems are at greatest risk of contracting COVID-19.⁵ In addition, people living in densely populated areas or rural areas with poor access to health care, living in congregate housing and multi-generational households, and those who work in the service industry also have a high risk for contracting COVID-19.⁶ This includes many racial and ethnic minorities, immigrants, and refugees.⁷

Requiring people to practice social distancing and undergoing self-quarantine and/or self-isolation are public health mitigation strategies and actions many countries have used to control and prevent the widespread of COVID-19.^8,9 In some countries, such as the United States and Canada, residents have been asked to practice social distancing. That is, to keep at least 2 m distance from other people, not to gather in groups, and to stay out of crowded places and avoid mass gatherings. In other countries, such as Italy, Spain, and China, residents have been required to self-quarantine in their homes or elsewhere and to limit movement outside for extended periods of time or at all. Persons ill with COVID-19 are told to self-isolate in places separate from others to avoid spreading the illness. In addition, schools and many jobs have transitioned to online to mitigate the effects of the pandemic. Restaurants, gyms, parks, community centers, and other public places used for social activities and recreation have closed in response to COVID-19, resulting in significant disruptions and changes in everyday schedules for work, school, recreation, and social engagement routines. Given COVID-19 closures and changes with reductions in daily movement, what is the impact on physical activity (PA) or exercise routines?

PA has been shown to be vitally important in improving the human immune system and reducing risk for diseases and health conditions during normal circumstances and in the current precarious conditions. In this special topic of the Journal of Sport and Health Science, we address this important public health issue by inviting researchers from around the world to present unique and pertinent topics about PA during these challenging times. Within this context, the specific topic covered in this Issue range from the impact of COVID-19 on PA, physical and mental health benefits of PA, practice and promotion of PA, to setting a global public health research agenda on PA.

In a review article, David Nieman provides an overview of exercise immunology with an important public health message of engaging in moderate-intensity exercise training for enhancing the immune system and negating the negative impact attributable to aging, obesity, and physical inactivity during this COVID-19 pandemic. Two original research study articles model the impact of COVID-19 on childhood obesity and on children's adherence to movement guidelines. Using the national kindergarteners’ body mass index data from a U.S. cohort study, Ruopeng An projects the trajectory of standardized body mass index and childhood obesity prevalence from April 2020 to March 2021 under various scenarios of school closures and restricted PA. Findings from An's study show an increasing trend over the projected time horizons in both BMI values and obesity prevalence with differences noted among gender and race/ethnicity groups. Similarly, applying a classification decision tree analysis to a national sample of Canadian parents of young children, Guerrero and colleagues examine profiles of children aged 5–17 years who are more or less likely to meet the 24-h Movement Behavior Guidelines during the COVID-19 lockdown period. Findings from their study show associations between several key demographic and parental factors and children's PA, screen time, and sleep, with parental perceived capability to support their children's movement behaviors and restrict screen time being an important influence in strategizing and promoting PA among children during the challenging times of the COVID-19 pandemic. Two opinion articles share information relevant to PA practice. In an effort to address the impact of COVID-19 on PA practices on children and youth in China, Chen et al. provide guidelines for administrators, physical education teachers, and parents when reintroducing children and youth to PA following a prolonged COVID-19 quarantine period. Similarly, Jurak et al. present best practices from a Slovenian viewpoint for ways children, adolescents, and adults can engage in PA during the quarantine period. In a final article, in addressing the importance of establishing a public health research agenda that can reveal the effects of COVID-19 on PA, Sallis and colleagues outline several important research areas aimed at understanding the impact of the pandemic on PA. Within a behavioral epidemiology framework, the authors propose emergent topics that focus on (a) PA as a mitigation strategy to moderate the impact of the coronavirus; (b) the development of PA measurements that are relevant in a pandemic context; (c) changes in PA behaviors; (d) reducing disparities in PA; (e) developing and evaluating interventions that take into account social, cultural, and built environmental factors to increase PA for COVID-19 prevention and treatment; and (f) translating the research into practice and policy for the current and future pandemics.

Collectively, these papers provide a snapshot of the importance of initiating and/or maintaining PA during and after the COVID-19 global pandemic. They also address the importance of establishing a public health research agenda and social systems to advance knowledge about PA during and after COVID-19 and to assure all persons have an equal opportunity to engage in PA behaviors, respectively. In viewing multiple health benefits of PA, we are reminded that PA is a behavior that lends itself to a coordinated, multidisciplinary team approach to address adequately its multiple dimensions. This approach is especially relevant in the presence of the COVID-19 global pandemic. From this perspective, we hope the articles in this special topic will serve as both scientific and public health impetus for stimulating research ideas that will lead to a better understanding of the impact of PA in helping boost the immune system, ameliorate symptoms, lower the risk of infection from the exposure to the coronavirus, and identify strategies to help children and adults remain physically active during the global pandemic.

Competing interests

The authors declare that they have no competing interests.