The current global pandemic of COVID-19 has forced to the implementation of strict emergency measures and restrictions to stop the virus from spreading in almost every country around the globe. Some of the measures are quarantines, social distancing, home confinement, and the complete shutdown of several cities, including regions. These necessary actions to prevent the virus from spreading may cause vast problems in the mental and physical health of the population.
The psychological effects of this pandemic can have long-term consequences that affect not just the people quarantined but also the healthcare workers (Brooks et al., 2020); thus, it is highly relevant to find strategies to better deal with such strict conditions. One important intervention to reduce the psychological impact of pandemic periods is physical exercise. Physical exercise is often used synonymously with physical activity, which can be misleading. Physical activity is defined as any bodily movement produced by the contraction of skeletal muscles and is an umbrella term that includes subcategories such as sports, leisure activities, dance, and physical exercise, which itself is defined as every planned, structured, repetitive, and purposeful intervention (Wegner et al., 2020). In any case, due to restrictions on the free movement of people, both physical activity and physical exercise get drastically reduced during quarantine and shutdown situations, with counterproductive effects.
Depression, posttraumatic stress, acute stress disorder, exhaustion, detachment from others, anxiety, emotional exhaustion, and irritability, among other trauma-related mental health disorders, have been seen to affect people under quarantine (Brooks et al., 2020). Physical activity and physical exercise interventions have been shown to produce positive impacts in most of these disorders (Zschucke, Gaudlitz, & Ströhle, 2013), as well as beneficial effects on common problems during quarantine times like frustration and boredom (Foye, Li, Birken, Parle, & Simpson, 2020). The largest number of studies have investigated physical exercise effects on depressive symptoms. Two articles aimed to review meta-analyses that focused on the effects of physical exercise on depressive outcome measures in children and adolescents (Wegner et al., 2020) and adults (Wegner et al., 2014). A medium effect size was found in the general effect size analysis of the included meta-analyses regarding physical exercise relieving depressive symptoms in the youth (Wegner et al., 2020). Similar results were found in older individuals, where the effect sizes pointing toward the intervention group was also medium ( Wegner et al., 2014). Besides, the positive physiological side effects of physical exercise, which include lower risk of developing hypertension, stroke, osteoporosis, diabetes, metabolic syndrome, and obesity, as well as a decreased risk for several cancers, have been widely demonstrated (American College of Sports Medicine, 2017). A therapeutic effect has additionally been described in 26 different chronic diseases (Pedersen & Saltin, 2015). Physical exercise can also be seen as a cost-effective treatment approach for application in resource-poor settings (Budde, Akko, Ainamani, Murillo-Rodríguez, & Weierstall, 2018).
In terms of physical inactivity, studies have shown that even short periods of physical inactivity damage the physical health of people with previous pathologies as well as healthy people (Bowden Davies et al., 2018), whereas an increase in habitual physical activity has been cross-sectionally associated with greater emotional well-being in a sample of 5,451 men and 1,277 women (ages 20–88 years; Galper, Trivedi, Barlow, Dunn, & Kampert, 2006).
A recent study (Chen et al., 2020) recommended exercising under quarantines for at least 30 min with moderate intensity every day and/or at least 20 min with vigorous intensity every other day, which is in line with the general recommendations from the second edition of the Physical Activity Guidelines for Americans (U.S. Department of Health & Human Services, 2018), which advocates for 150–300 min a week of moderate-intensity, or at least 75 min a week of vigorous-intensity, physical activity (or a comparable combination of both) and two sessions per week of strength training.
It can be advisable to increase the intensity of the physical exercise to enhance the exercise effect on mental health (Budde, Velasques, et al., 2018; Gronwald et al., 2018). However, for reasons of stimulus effectiveness, every factor of a physical exercise prescription (e.g., volume, intensity) should be individually adapted and controlled (Gronwald & Budde, 2019; Gronwald et al., 2019); thus, professional advice is always desirable.
Because of the pandemic situation, within several regions, exercising outdoors, in gyms, and groups is no longer allowed, and other alternatives must be found to maintain a mental and physical balance. However, at least exercising space is necessary; it is difficult to keep up an active lifestyle during quarantine in resource-poor settings with a limited floor area per person in a household. Although it is still under debate whether physical exercise is better accomplished indoors or outdoors, it seems clear that the amount of social contact and support from others increases the beneficial effects of physical exercise interventions (Burke, Carron, Eys, Ntoumanis, & Estabrooks, 2006).
In conclusion, physical activity and physical exercise might be key factors to help the population to better tolerate pandemic periods at both the mental and physical levels. Therefore, both should be considered as effective factors to lessen the impact of these periods and should be included in general healthcare and prevention strategies.
