COVID-19: Effects of Pandemic Related Restrictions on Physical Activity, Screen Time, and Mental Well-being in German adolescents
Abstract
Abstract:Objective: To describe the impact of the COVID-19 pandemic-related restrictions (PR) in April and May 2020 on physical activity (PA), sedentary screen time (SST), and mental well-being (MWB) in German adolescents, and to analyze associations between these variables. Methods: The Münster District Government invited all secondary school students (aged 11–17) in the region to take part in the online survey that assessed PA, SST, and MWB. For data analysis, we calculated descriptive statistics and ran linear regression analysis. Results: 1,038 students (627 [60.4%] female; 14.18 [± 1.97] years) were included in the analysis. During the PR, a marked decline in overall PA (p < .001) and a significant increase (p < .001) in SST were observed. One-third of the students reported worrying more and being less satisfied with their lives since PR. A decrease in life satisfaction (ß = –.524, p < .001) as well as an increase in general worrying (ß = –.336, p = .015) were associated with a decrease in PA during PR. Conclusion: The results show that the restrictions led to a decrease in physical activity, which may have detrimental effects on the students’ mental and physical health.
Zusammenfassung: Fragestellung: Die Studie soll die Auswirkungen der pandemiebedingten Kontaktbeschränkungen im April und Mai 2020 auf die körperliche Aktivität, die sitzend verbrachte Bildschirmzeit und das psychische Wohlbefinden bei deutschen Jugendlichen beschreiben und mögliche Zusammenhänge analysieren. Methodik: Die Bezirksregierung Münster lud alle Schüler_innen der weiterführenden Schulen (11–17 Jahre) im Regierungsbezirk ein, an einem Online-Survey teilzunehmen, der die körperliche Aktivität, die Bildschirmzeit und Aspekte des psychischen Wohlbefindens erhob. Die Datenanalyse erfolgte im Rahmen deskriptiver Statistik und linearer Regressionsanalyse. Ergebnisse: 1038 Jugendliche (627 [60.4%] weiblich; 14,18 [± 1.97] Jahre) wurden in die Analyse einbezogen. Während der Kontaktbeschränkungen nahm die körperliche Aktivität deutlich ab (p < .001), wohingegen die Bildschirmzeit signifikant zunahm (p < .001). Ein Drittel der Schüler*innen gibt an, sich mehr Sorgen zu machen und weniger zufrieden mit ihrem Leben zu sein. Die Abnahme der Lebenszufriedenheit (ß = –.524; p < .001) als auch die Zunahme von Sorgen (ß = –.336; p = .015) waren mit einer Abnahme der körperlichen Aktivität assoziiert. Schlussfolgerungen: Die Ergebnisse deuten darauf hin, dass die Kontaktbeschränkungen zu einer Abnahme der körperlichen Aktivität geführt haben, was sich ungünstig auf die psychische und somatische Gesundheit der Jugendlichen auswirken kann.
Introduction
Physical inactivity and sedentary behavior are major risk factors for physical and mental ill-health as well as for a decrease in physical and mental well-being (Kohl et al., 2012; Poitras et al., 2016; Saunders et al., 2016; WHO, 2020).
On 16 March 2020, the German federal state governments took strict measures to contain the SARS-CoV-2 pandemic. These included closing schools, sports clubs, gyms, playgrounds, and parks, resulting in a shutdown of most areas of organized physical activity (PA). It was to be expected that such measures would have a strong impact on everyday activity and exercise patterns (Guan et al., 2020; Martinez-Ferran et al., 2020).
While emerging studies on adults have already provided a preliminary overview of collateral COVID-19 effects on PA, sedentary behavior, and mental health (Ammar et al., 2020; Bezerra et al., 2020; Constandt et al., 2020; Lesser & Nienhuis, 2020; Mazza et al., 2020; Qiu et al., 2020; Stanton et al., 2020; Talevi et al., 2020; Wang et al., 2020; Zhang et al., 2020), our current understanding of the COVID-19 influence on health-related lifestyle factors and mental well-being (MWB) of children and adolescents is still quite limited.
Studies from Canada, China, Poland, Czechia, and Austria on children and youth provide evidence of an adverse impact of the COVID-19 restrictions on movement and play behaviors (Greier et al., 2021; Luszczki et al., 2021; Moore et al., 2020; Stverakova et al., 2021; Xiang et al., 2020). From earlier studies on PA behavior in children and adolescents, we know that school-related activities, sports participation, and active transport make up a major part of their daily PA routines (Guan et al., 2020; Hoffmann et al., 2019; Parker et al., 2019). Consequently, negative changes in students’ activity and exercise behavior had been observed even during national holidays (Aphamis et al., 2017; Weaver et al., 2019). For this reason, it was expected that the impact of the COVID-19 restrictions on PA would be particularly pronounced in this group.
As emerging studies show, a further symptom of the social distancing measures is also a serious increase in sedentary screen time (SST) (Greier et al., 2021; Moore et al., 2020; Pietrobelli et al., 2020; Xiang et al., 2020). For example, a considerable increase in gaming was observed and game download reached a record high during the corona pandemic in the United States (King et al., 2020; Ko & Yen, 2020).
Several studies revealed significant associations between PA, SST, MWB, and mental health, including in children and adolescents (Munasinghe et al., 2020; Wunsch et al., 2021; Zhang et al., 2020; Zhou et al., 2020). Whereas a positive impact of PA on the mood states of children and adolescents was found (Zhang et al., 2020), a highly significant negative association between depression and physical exercise was shown in female adolescents (Zhou et al., 2020). In a recent longitudinal study that included adolescents between 13 and 19 years of age, physical distancing and social restrictions were associated with a decrease in PA, an increase in SST, and decreases in well-being (Munasinghe et al., 2020). PA was determined as an important coping strategy associated with well-being during pandemic times (Pigaiani et al., 2020). On the other hand, however, an increase in overall PA during pandemic restrictions (PR) was found in a representative German sample of children and adolescents (Schmidt, Anedda, Burchartz, Eichsteller et al., 2020; Wunsch et al., 2021).
To contribute to a more comprehensive picture of the collateral effects of pandemic restrictive measures on adolescents’ health-related lifestyle in Germany, the PAW Survey (1) describes the impact of the COVID-19 contact restrictions in Germany on PA, SST, and indicators of MWB in adolescents and (2) identifies factors associated with PA during PR. Against the background of the already existing body of evidence, we hypothesize that the social-distancing measures employed in Germany in April 2020 led to a decrease in PA, an increase in SST, and a deterioration of MWB in secondary school students.
Materials and Methods
Sample Recruitment
The study sample included students aged 11 to 17 attending secondary schools in northwestern Germany. The students were recruited from 22 April till 19 May 2020 in two ways:
- 1.Via e-mail, the Münster District Government invited 138 secondary schools (about 110,000 students) in the region to take part in the online survey. Of these, about 72,000 students attend a Gymnasium and 38,000 attend other secondary schools.
- 2.Using social media channels and local newspapers, the University Hospital Münster Communication Department reached out to further students and their families in the district.
Via an online link, the students could reach a LimeSurvey website on a Münster University server. On the website, the participants were automatically guided through the 38 items of the survey, which took about 20 minutes. Only fully completed surveys could be submitted. All questionnaires were submitted between 22 April 22 and 19 May, when the survey website went offline.
The study was performed in accordance with the declaration of Helsinki and approved by the Ethics Committee of the Medical Association of Westphalia-Lippe and the University of Münster (2020-259-f-S). All subjects gave written informed consent before the study.
Measures
Anthropometry
In the online survey, students were asked to specify their body height in cm and body weight in kg. Their BMI was subsequently calculated by dividing body weight by the square of body height (kg/m2). Individual BMI values were transformed into the Standard Deviation Score [SDS; (BMI-SDS)], using the LMS-Method (Cole & Green, 1992) based on German reference data for children and adolescents (Rosario et al., 2010).
Social, Environmental and Health Factors
To further characterize the study sample, we used self-developed questions related to (1) country of birth, (2) place of residence, (3) housing situation, (4) type of school, (5) Covid-19 status, (6) chronic diseases, (7) medication, (8) drug use, (9) alcohol use, and (10) smoking.
Physical Activity
Self-reported PA was measured based on an item of the German Motoric Modul Physical Activity Questionnaire (MoMo-PAQ). This questionnaire is part of the representative German KiGGS study (German Health Interview and Examination Survey for Children and Adolescents) and refers to the WHO recommendations on PA in children and adolescents (Schmidt et al., 2015):
“On how many days of a normal week have you been active for at least 60 minutes a day?”
“Physical activity includes all activities in which your heart beats faster and your breathing is deeper and faster as well. Physical activities can be sports and exercise, playing with friends, or walking to school. Some examples are running, walking, inline skating, cycling, dancing, skateboarding, swimming, playing basketball, or soccer, or going surfing.”
“Since the corona-restrictions, I worry … rather less = 1, … the same = 2, … rather more = 3”.
“Since the corona-restrictions, I am … rather more satisfied with my life = 1, … similarly satisfied with my life = 2, … rather less satisfied with my life = 3.”
To make sure every participant understood what is meant by “physical activity,” we included the following explanation:
To enable a prepandemic and during-pandemic comparison, the participants were asked to self-report their PA by answering the following, slightly altered questions:
- 1.“Before the corona-restrictions (during the past 6 months): On how many days of a normal week have you been active for at least 60 minutes a day?”
- 2.“During the corona restrictions: On how many days of a ‘normal’ Corona week have you been active for at least 60 minutes a day?”
As a variable describing the pre-PR vs. during-PR differences, we calculated “delta PA” (PA during-PR – PA pre-PR). Positive delta PA values indicate an increase, whereas negative values indicate a decrease.
Notwithstanding the item alterations for this survey, data obtained with the MoMo-PAQ have been shown to be sufficiently reliable (test-retest reliability: ICC = 0.68). Correlation coefficients with accelerometry data are rather low (r = 0.29) (Jekauc et al., 2013).
Screen Time
To measure SST, the participants were asked to estimate the time spent on watching television, using a game console, a computer, and a smartphone on a 5-point scale (Lange et al., 2017) before and during PR: (1) not at all; (2) about 30 minutes; (3) about 1–2 hours; (4) about 3–4 hours; (5) more than 4 hours.
In order to obtain a total SST variable, we aggregated and totaled the time spent on each medium as performed in the German KiGGS health survey (Lange et al., 2017): not at all = 0 hours, about 30 minutes = 0.5 hours, about 1–2 hours = 1.5 hours, about 3–4 hours = 3.5 hours, more than 4 hours = 5 hours. Total SST was then recategorized into (1) 0 to <4 hours/day, (2) 4 to <8 hours/day, and (3) ≥ 8 hours/day.
As a variable describing the pre-PR vs. during-PR differences, we calculated “delta SST” (SST during-PR – SST pre-PR). Positive delta SST values indicate an increase, whereas negative values indicate a decrease.
Mental Health and Mental Well-Being
Mental health problems before PR were assessed using the Strengths and Difficulties Questionnaire (SDQ). The students were asked to estimate how the SDQ statements apply to them considering the 6 months before PR. The SDQ (Goodman, 1997) includes five subscales (emotional problems, hyperactivity/inattention, conduct problems, peer relationship problems, and prosocial behavior). The scores of the five subscales are summed up to a total difficulties score.
To obtain an indicator of MWB during PR, we used two self-developed items. On a 3-point scale, coded “1”, “2”, and “3”, the students had to evaluate the changes regarding worrying and life satisfaction:
For further analysis, we aggregated points 1 and 2 (not more worried/not less satisfied) to achieve a binary pattern, juxtaposing those who experienced a deterioration of well-being with those who experienced no change or even an improvement of well-being.
Statistical Analysis
For descriptive statistics, we calculated frequencies (absolute frequencies and percentages), means, and the respective standard deviations. Paired two-sample t-tests were performed to detect prepandemic and pandemic differences related to the variables PA and SST. Additionally, differences between male and female students were analyzed using unpaired t-tests.
A linear regression model was performed to examine the association between the independent variables: age, sex, BMI-SDS, PA before PR, ∆ total SST (during PR minus before PR), SDQ total score, SDQ subscores, worrying since PR, life satisfaction since PR, and the outcome variable: ∆PA (during PR minus before PR).
Because our data indicate a homogeneous socioeconomic status (SES) (e. g., > 90 % attendance of Realschule/Gymnasium, 89 % reported to have a garden) we did not include this parameter as covariate. We calculated a sensitivity analysis including the dichotomous variable school type (1 = Gymnasium, 0 = other secondary schools). All analyses were explorative. They were performed with IBM© SPSS© Statistics (Version 24). p-values < .05 were considered significant.
Results
Sample Characteristics
1,060 students completed the online questionnaire, of which 22 had to be excluded because they were either too young (< 11) or too old (> 17). Table 1 shows the characteristics of the study group (total N = 1,038). 60 % were females, mean age was 14.18 (± 1.97) years. Mean BMI parameters were in the normal range. No student had been in hospital for COVID-19 treatment. Only two students (0.2 %) were tested positive for COVID-19. Nevertheless, 2.7 % of the students had already been in quarantine and 1.9 % were in quarantine when completing the questionnaire.
Physical Activity
On average, under prepandemic conditions, the participants reported meeting the WHO recommendation of at least 60 minutes of moderate to vigorous intensity PA on 4.48 (± 1.81) days of the week. During the contact restrictions, the number of days dropped significantly (p < .001) to 3.33 (± 2.31) days (Table 2).
The decrease of PA was significantly (p = .001) more pronounced among males. In this group, we observed a mean loss of 1.44 (± 2.31) days per week compared to 0.96 (± 2.20) days among females.
While under prepandemic conditions 17.7 % of the students (male: 20.0 % and female: 16.3 %) met the WHO recommendations of daily PA (WHO, 2010), this number dropped slightly under COVID-19 conditions to 15.6 % (male and female: each 15.6%).
In total, during the pandemic, there was an inactive group of 25.9 % of the students who met the recommendation on only 1 day or not at all, compared to 5.3 % under pre-COVID-19 conditions.
Screen Time
Compared to prepandemic conditions, there was a significant (p < .001) increase in total SST during the pandemic restrictions (Table 3). The number of students reporting a daily SST of 8 hours and more rose from 19.4 % before the pandemic to 45.4 % during the shutdown (Table 3). Regarding total SST, there is no significant difference between the sexes, before as well as during pandemic restrictions (Table 3). There is a significant increase (p < .001) for all four analyzed types of media, both in males and females.
However, focusing on the four different types of media individually, we found significant differences in the media consumption patterns between males and females.
During PR the females reported watching significantly more TV (p = .011) than the males. The use of game consoles was significantly higher in males than in females, both before and during PR (p < .001). The female participants used smartphones for significantly (p ≤ .001) longer periods of time each day, both before and during PR. No significant difference was found for computer use between males and females.
Mental Health and Well-Being
Regarding the 6-month period before the pandemic, the mean total difficulties score of the respondents is 10.79 (Table 4). This value is well in the range considered normal (0–15) (www.sdqinfo.org) (Goodman et al., 1998). The mean values of the five subscales are also within the normal range. However, while 82.9 % have normal total SDQ-scores, 10.4 % (108 students) have an increased total score, and 6.7 % (70 students) have an abnormal SDQ-score.
More than one-third of the respondents (37.1 %) report worrying rather more since the contact restrictions. Again, this value is higher among the females (41.9 %) compared to the males (29.7%). Nevertheless, there is also a group of 12.8 % of the students who worry rather less since the pandemic (Table 4).
Regarding life satisfaction, 37.1 % of the students report being rather less satisfied with their lives since the contact restrictions. With 41.9 % compared to 29.7 %, this value is higher among the females than among the males. However, a considerable group of students (10.1 %) also report being rather more satisfied with their lives during the pandemic.
Associations Between Physical Activity, Sedentary Screen Time, and Mental Well-Being
The regression model explained 24 % of the variance of ∆PA. All SDQ variables were not significantly associated with the outcome variables (Table 5). Concerns and life dissatisfaction since PR were negatively associated with ∆PA (β = –.336, p = .015 and ß = –.524, p < .001, respectively). In addition, the covariates sex (β = .368, p = .007), PA before PR (β = –.431, p < .001), and ∆ total SST (β = – .190, p < .001) had a significant impact on ∆PA. After performing the sensitivity analysis including school type as covariate, we found β coefficients of the other covariates had changed only marginally. School type was not significantly associated with ∆PA (β = –.126, p = .395).
Discussion
As hypothesized, we found a strong decrease in reported daily PA, a notable increase in daily SST, and indicators pointing toward a deterioration of the students’ MWB. Most students attend a Gymnasium or Realschule, had access to a garden, and were physically and psychologically healthy.
Physical Activity
In our survey, the number of days on which the students met the WHO recommendation of at least 60 minutes of moderate to vigorous PA per day decreased significantly. Despite certain methodological differences, this finding is supported by the results of a survey on Canadian children and adolescents, in which the participants met the WHO recommendation on 3.55 (children aged 5–13) and 2.59 (adolescents aged 14–17) days per week during a social distancing period in April 2020 (Moore et al., 2020). However, the observed decrease in daily PA is not in line with the findings of a recent German study from Karlsruhe, in which an overall increase of PA was found for a representative sample of children and adolescents during the shutdown period in April 2020 (Schmidt, Will et al., 2020). Although Schmidt and colleagues observed a decline in sports and exercise activities, a marked increase in habitual physical activities overcompensated for the losses in sports and exercise. In Schmidt et al., activities like helping with housework and gardening were explicitly defined as part of PA, which was not the case in our study. We assume that the differences between the two studies in terms of overall PA and adherence to the WHO guidelines might partly be explained by a slightly different understanding of PA on the part of the participants. A further aspect, possibly explaining the different findings, might be the SES of the participants. As Schmidt et al. discuss in their study, children and adolescents from lower SES backgrounds do not seem to rely as strongly on organized sports and exercise activities as those from higher SES backgrounds (Schmidt, Anedda, Burchartz, Oriwol et al., 2020). Although we did not explicitly measure SES, attending a Gymnasium, which most students in our study do, can still be regarded as an indicator of a higher SES (Büchler, 2016). There is an ongoing discussion on the relationship between SES and PA with studies hinting at a certain social gradient (Heradstveit et al., 2020). Higher SES, for its part, is associated with better health and health-related behavior in general (Waldhauer et al., 2018) and a higher total physical activity level and less screen time (Auhuber et al., 2019; Poulain et al., 2018) in particular. Together with the privileged housing situation, it must be acknowledged that the investigated group of students was probably better positioned for a long period of social distancing than the average student in Germany. In the present study, school type as covariate was not significantly associated with ΔPA, which may be due to the fact that the study sample is very homogeneous in terms of school type (> 90 % Gymnasium and Realschule).
The already existing gap between the most active and the least active students seems to have widened during the lockdown. According to Manz et al. (2014), all those students are considered “inactive” who meet the WHO recommendations on less than 2 days per week. Considering the negative short- and long-term impact of inactivity on somatic (de Rezende et al., 2014; Kumar et al., 2015; Wu et al., 2017) and mental health (Hoare et al., 2016; Lachytova et al., 2017; Suchert et al., 2015), this finding is alarming.
In contrast to the Canadian findings (Moore et al., 2020), in our study, the decline in PA was significantly larger in males compared to females, and male sex was identified as a risk factor for a decrease in PA during PR (∆PA). Under “normal” (prepandemic) conditions, male adolescents are usually found to have been more physically active than female adolescents (Butt et al., 2011; Krist et al., 2020; Manz et al., 2014). However, the effect might be explained by gender-specific differences in physical exercise motivation (Navarro et al., 2020) and their effects on the students’ exercise behavior during a period of contact restrictions.
Against the background of trajectory studies showing that PA behavior at a young age mostly persists over time (Hayes et al., 2019; Mikalsen et al., 2020), a positive association between PA before PR and during PR was to be expected. Thus, students on an active trajectory seem to keep up a rather active lifestyle even under unfavorable conditions, whereas less active students stay less active during the pandemic. On the other hand, the decrease of PA during the pandemic might be stronger among active students than among less active students due to their higher baseline levels of PA (Auhuber et al., 2019).
Screen Time
We found a significant increase in total SST during PR. Regarding the total SST score, it must be considered that the accumulation of the single SST items also leads to an accumulation of the errors in these items.
In the face of a large Chinese study (Xiang et al., 2020), a strong increase of SST had to be expected in Germany as well. In our study, under PR conditions, 85.2 % of the students reported a daily total SST of more than 4 hours. This result is also supported by Schmidt and colleagues who found mean recreational SST values of 251.6 minutes/day (11–13-year-olds) and 290.2 minutes/day (14–17-year-olds) during the first shutdown period in Germany (Schmidt et al., 2020a).
Regarding total SST, no significant difference was found between males and females, neither during nor before pandemic restrictions. Nevertheless, media-use patterns seem to be gender-specific. Males used game consoles more extensively, both in prepandemic and pandemic times. Female participants used smartphones for significantly longer times each day, independent of pandemic restrictions. These results support an extensive body of evidence on the leisure time behavior of male and female adolescents (Auhuber et al., 2019; Fischer-Grote et al., 2019).
Considering possible associations of SST and PA, we found that an increase in SST was associated with a decrease in PA. Despite the small effect size, this finding is in line with Xiang et al., who also found a significant correlation between both variables (Xiang et al., 2020).
Mental Health and Well-Being
The SDQ results show that most students in our cohort can probably be considered mentally healthy. Regarding MWB, 37.1 % of the participants reported to worry more and to be less satisfied with their lives since PR. For both variables, worrying and life-satisfaction, females seem to experience more negative changes due to PR than males. This is in accordance with a current review by Marques de Miranda et al. (2020), in which the authors identified female sex as a risk factor for several mental distress measures.
With social isolation being an important risk factor for poor mental health and well-being (Fegert et al., 2020; Hall-Lande et al., 2007), a marked change in MWB had to be expected. However, our regression model revealed significant associations between these two variables (worrying/life-satisfaction) and the changes in PA during PR. According to our model, life-satisfaction during PR is the strongest predictor variable for a decrease of PA during PR. This finding is in line with several studies showing associations between PA, MWB, and mental health (Lubans et al., 2016). For those experiencing psychological distress, PA and exercise being easily accessible could be of paramount importance to overcome motivational barriers (Firth et al., 2016) and to prevent the vicious cycle of a primary reduction in PA, in combination with an increase in SST, which leads to a deterioration of physical and mental health, which, in turn, leads to an even further reduction of PA and an even further increase in SST (Xiang et al., 2020).
Strengths and Limitations
The study included a high number of students and analyzed PA, SST, and certain aspects of MWB in a combined approach in German. The cohort is not representative of the whole adolescent population. 76.2 % of the students in our cohort attended a Gymnasium compared to a North-Rhine Westphalian average of 42.8 % (Ministry for School and Education of the State of North Rhine-Westphalia, 2021). Due to limitations of the online questionnaire, some confounding variables could not be included in the analysis (exercise motivation, individual stressors, socioeconomic status, and quality-of-life variables). Furthermore, it must be acknowledged that the findings of a self-report online survey do not always reflect everyday reality and might be confounded by a social desirability bias. Additionally, the correlation coefficient of the physical activity questionnaire with accelerometry is very low (Jekauc et al., 2013). Regarding the total SST score, it must be considered that the accumulation of the single SST items also leads to an accumulation of the errors in these items, and that the given time categories did not exceed ≥ 8 hours per day. The latter might lead to an underestimation of the actual amount of media consumption.
On the other hand, the impact of the pandemic restrictions could be clearly highlighted, and our hypotheses could be tested. Because of residual confounding and reverse causation our study could detect only associations but not their direction. As our survey started in the first weeks of the pandemic restrictions in Germany, the confounding effect of the retrospectivity of the questions in the SDQ is assumed to be low.
Conclusions
The contact restrictions implemented in the initial period of the COVID 19 pandemic in Germany had a marked collateral impact on adolescents’ PA behavior, SST, and MWB. All three factors were found to be associated and, thus, can be regarded as important prognostic factors for health trajectories in times of social isolation and pandemic-related contact restrictions.
For these reasons, schools, sports clubs, and other leisure and sports providers should develop sports and exercise programs, compatible with pandemic restrictions, to try to increase PA in children and adolescents during such times.
Child and adolescent psychiatrists should ensure continuity of care during all phases of the pandemic to prevent a deterioration of their patients’ mental health status.
Literature
We thank all participants for taking part in the survey. We acknowledge the continuous support of Uwe Eisenberg and Thomas Michel (Münster District Government).
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