Schools are a key setting for promoting physical activity in children. There is little evidence on the potential of widely implemented programs to improve the quality of physical education (PE). The aim was to assess the effects of a short training course for classroom teachers on the quality of PE, assessed as activity time during PE. A quasi-experimental study was conducted with 6 intervention (N = 86) and 13 control classes (N = 151). Schools were selected in a random procedure (26.9% participation). Participation in children was 86.2% (mean age 7.8 years, 48.9% girls). Physical activity was assessed objectively using accelerometers. Effect on time spent in sedentary, moderate, vigorous and moderate-to-vigorous (MVPA) activities, steps and counts/minute during PE were analysed using t-tests and mixed linear models. Physical activity time increased significantly in the intervention but not in the control group between baseline and follow-up (relative increase in moderate-to-vigorous physical activity of 12% in intervention group). Increases were strongest in girls and in children inactive at baseline. In the mixed linear models adjusted for clustering, the effects were significant in girls for vigorous activities, sedentary time and counts/minute, in inactive children for steps. Results indicate that a short training course for classroom teachers can have subtle positive effects on physical activity time during PE. Girls and the most inactive children at baseline profited most from the intervention.
The beneficial effects of regular physical activity on children’s physical and mental health are well recognised [
In Switzerland, the KISS study is an example of a school-based intervention that effectively increased physi- cal activity levels in children [
As an extension of Y + S operating since 2008, Y + S Kids targets children aged 5 to 10 years. Y + S Kids re- ceived an additional budget of CHF 20 Mio (around €25 Mio) per year. The program is organised in two set- tings, namely in schools and in sport clubs. The aim of the school setting is to reach all children, in particular the less active ones, by providing one or more additional PE lessons per week in the frame of extracurricular sports. Classroom teachers offering these additional lessons are trained during a two-day course. The aims of Y + S Kids are to improve the quality of sports lessons and are mainly based on sport pedagogic approaches. However, one quality criterion for “good” PE and sports lessons is a high activity time [
Y + S Kids has not only the potential to quantitatively increase physical activity through the additional Y + S Kids lessons, but may also improve the quality of the regular three PE lessons per week required by Swiss fed- eral law through the teachers’ training course. In most parts of Switzerland, PE in primary school is given by classroom teachers and not specialists, and the two-day training course should improve their PE teaching skills with the result—among others—of more activity time for children. This could be especially important for less active subgroups of children, such as girls [
The potential for the nation-wide implementation of Y + S Kids is based on the short and feasible intervention (two-day training course for classroom teachers, additional PE lesson for children in the context of extra-curri- cular sports), the sufficient and long-term funding, and the available organizational structures and processes set up since the 1970ies in the frame of Y + S. The effectiveness of the program has not yet been evaluated.
The aims of this study were to describe physical activity time during PE lessons in school children aged 7 - 9 years and to assess changes in physical activity time during PE after the classroom teacher had participated in Y + S Kids teachers’ training course. A special focus was on potential sex differences and differences between inactive and active children at baseline. Furthermore, the acceptance and satisfaction with the Y + S Kids teach- ers’ training course will be reported.
A quasi-experimental study was conducted between April and September 2012 including 6 intervention (n = 86) and 13 control classes (N = 151). Schools were selected in a random-based multi-step procedure in cooperation with the public administration of the Swiss Canton of Aargau in autumn/winter 2011/12. Within schools, inclu- sion criteria for teachers and their classes were that participating teachers had not yet participated in a Y + S
Kids teachers’ training course, that they taught first, second or third graders and that they were going to keep the same class in the school year 2012/2013. In total, 72 schools were contacted; 31 (43.1%) did not meet the inclusion criteria (i.e. there were no teachers fulfilling the inclusion criteria). 19 (46.3%) of the eligible schools declined to participate, 5 (12.2%) could not be reached and 6 (14.6%) could be reached but did not answer back. If a school was eligible and interested in the study, the head of the school contacted eligible teachers and provided their names to the study team if they wanted to participate. The study team then contacted the teachers directly. Overall, 11 (26.9%) of the eligible schools participated in the study, two among them providing two classes each, yielding a total of 13 classes. Finally, 6 more classes from 3 additional schools were recruited with a snowball system, totalling 19 classes from 14 schools. Those teachers willing to participate in the intervention arm of the study were allocated to the intervention group, the other teachers to the control group. All teachers were aware that we were interested in the evaluation of the Y + S Kids teachers’ training course, however they were not aware that we looked specifically at time spent actively during PE lessons.
Intervention and control classes were not in the same schools. The sample size calculation was based on the following assumptions: based on another Swiss study [
In each class, parents were informed about the study by a member of the research team during an information event. Written parental consent was obtained for all participating children. The study was approved by the Eth- ics Committee of the Canton of Aargau, Switzerland. Due to organisational issues, the study could not be blinded; teachers were aware of the group they were in and the group allocation of the classes was known to the assessors. However, teachers were not aware that activity time during PE lessons would be analysed specifically.
Baseline assessments took place in April/May 2012, follow-up assessments in September 2012. Physical activity was measured objectively using accelerometers (Actigraph GT3X or GT3X+, Pensacola, FL, USA). The chil- dren were asked to wear the devices during 7 consecutive days on the right hip while awake. Detailed instruc- tions were given during a fitness test organised in the frame of this study. An accelerometer was attached to each child’s hip by a member of the research team. Children were asked to remove the accelerometers while sleeping and during water-based activities. An epoch time of 5 seconds was chosen in order to account for the short bouts of moderate and vigorous activities usually observed in children [
For the present analyses, physical activity data during regular PE lessons were included while the extra-cur- ricular Y + S Kids course for children was not. Generally, three PE lessons per week are compulsory in Swit- zerland. However, one lesson per week may be replaced by a swimming lesson (during which children did not wear the accelerometer). The days and time of PE lessons were available from the teachers. Information on whether a child had participated in the lesson was available from a short diary that the parents completed during accelerometer assessments. A child was included if data was available for at least one PE lesson both at baseline and follow-up. On average, 2.1 and 2.4 PE lessons per class took place at baseline and follow-up, respectively. Accelerometer data of the children was available for 91.4% of lessons at baseline and for 82.8% at follow-up with no differences between groups, gender and activity level at baseline. The software Actilife 6 was used to ex- tract and process the data. Time spent in sedentary (0 - 25 counts/15seconds), light (26 - 573 counts/15seconds), moderate (574 - 1002 counts/15seconds) and vigorous (≥1003 counts/15seconds) physical activity was calculated based on cut points developed by Evenson et al. [
During the fitness test, height and weight were measured and body mass index (BMI) was calculated. Age- and sex-specific cut points were used to define overweight [
The intervention was a standardised two-day Y + S Kids training course for classroom teachers, which was held on a weekend in June 2012. The aim of the training course was to support classroom teachers to plan and conduct PE lessons that are more age-specific and intense. The focus was practice-oriented, providing participants with a wealth of new didactical material such as model lessons, booklets or music CDs for physical activity and sports in young primary school children. A specific emphasis was given to organisational aspects such as giving children the opportunity to learn and experience different activities during most of the lesson. In addition, teachers had to learn about the specific administrative requirements of the Y + S Kids programme. Increasing physical activity time during regular PE was not an explicit goal of the teachers’ training course and was thus not communicated to the teachers as such.
A standard course evaluation took place among all course participants (N = 41, including the six teachers of the intervention classes) using questionnaires. Course satisfaction and practicability were assessed with five- point likert scales; course organization, infrastructure, content and instructors with open-ended questions. In ad- dition, the six teachers of the intervention classes were contacted by telephone in November 2012 to conduct a structured interview with open-ended questions. Teachers were asked about their satisfaction with the course five months later and their experiences in implementing course contents into the Y + S Kids course they offer for their students.
The outcome measures used were time spent in sedentary, moderate, vigorous and MVPA, as well as the total number of steps and the mean counts per minute during PE. Descriptive analyses included means and standard deviations. Unpaired t-tests were used for the comparison between intervention and control group and paired t-tests for the comparison between baseline and follow-up levels within groups in unadjusted descriptive analyses. Two-sided p-values were used and the significance level was set to p < 0.05. Regression models adjusting for clustering within classes were used to compare baseline and follow-up values between groups.
Tertiles according to MVPA during PE at baseline were calculated for the intervention and the control group separately in order to perform sub group analyses for the most inactive compared to the most active children.
Mixed linear models adjusted for sex, age, education of parents, child’s migrational background and over- weight were used to simultaneously analyse the effects of time and group. The reported values are the time × group interaction terms that allow identification of potential differences in changes between groups over time. For each model p values for two versions are presented, one without and one with taking into account clustering within classes (effect estimates remain the same irrespective of taking into account clustering). Analyses were carried out using STATA version 12 (StataCorp LP, College Station, Texas, 2011).
The 19 included classes comprised 340 children of which 293 consented to participate (86.2%). For the present analyses, only children with physical activity data of at least one PE lesson at baseline and follow-up were in- cluded (N = 237, 80.9% of participating children).
. Baseline characteristics of included children
Total | Intervention | Control | p | ||
---|---|---|---|---|---|
N | 237 | 86 | 151 | ||
Age, mean (SD) | Years | 7.8 (0.7) | 7.8 (0.5) | 7.9 (0.8) | 0.34 |
Girls, % | 48.9 | 51.2 | 47.7 | 0.61 | |
Overweight, % | 17.4 | 16.3 | 18.1 | 0.72 | |
Education father, % | High | 40.5 | 42.7 | 39.1 | 0.60 |
Education mother, % | High | 29.7 | 20.5 | 35.3 | 0.02 |
Migrant background child, % | Yes | 43.9 | 44.4 | 43.6 | 0.90 |
. Physical activity time during PE lessons at baseline and follow-up, by group, by sex
Baseline | Follow-up | p | Baseline | Follow-up | p | |
---|---|---|---|---|---|---|
Total | ||||||
Intervention group (n = 86) | Control group (n = 151) | |||||
Sedentary, mean min (SD) | 15.4 (4.9) | 13.5 (3.4) | <0.001 | 14.4 (4.0) | 14.1 (3.5) | 0.31 |
Moderate, mean min (SD) | 5.6 (1.6) | 6.0 (1.3) | 0.046 | 6.1 (1.5) | 6.2 (1.3) | 0.35 |
Vigorous, mean min (SD) | 6.8 (3.0) | 7.9 (2.8) | <0.001 | 8.2 (2.8) | 8.1 (2.9) | 0.53 |
MVPA, mean min (SD) | 12.4 (4.1) | 13.9 (3.3) | <0.001 | 14.3 (3.5) | 14.3 (3.4) | 0.93 |
Steps, mean (SD) | 1558 (491) | 1802 (359) | <0.001 | 1880 (406) | 1793 (360) | 0.02 |
counts/min, mean (SD) | 1699 (559) | 1924 (495) | <0.001 | 1920 (474) | 1926 (499) | 0.89 |
Boys | ||||||
Intervention group (n = 42) | Control group (n = 79) | |||||
Sedentary, mean min (SD) | 13.4 (5.2) | 13.1 (3.6) | 0.75 | 13.3 (3.6) | 13.2 (3.6) | 0.79 |
Moderate, mean min (SD) | 6.3 (1.7) | 6.2 (1.2) | 0.67 | 6.7 (1.5) | 6.5 (1.3) | 0.43 |
Vigorous, mean min (SD) | 7.8 (3.0) | 8.6 (2.8) | 0.11 | 9.0 (2.9) | 9.0 (2.9) | 0.97 |
MVPA, mean min (SD) | 14.1 (4.1) | 14.7 (3.2) | 0.32 | 15.7 (3.4) | 15.5 (3.3) | 0.76 |
Steps, mean (SD) | 1626 (551) | 1861 (360) | 0.01 | 2022 (416) | 1899 (372) | 0.04 |
counts/min, mean (SD) | 1878 (554) | 2016 (488) | 0.08 | 2058 (469) | 2078 (510) | 0.75 |
Girls | ||||||
Intervention group (n = 44) | Control group (n = 72) | |||||
Sedentary, mean min (SD) | 17.4 (3.6) | 13.9 (3.3) | <0.001 | 15.6 (4.0) | 15.1 (2.8) | 0.23 |
Moderate, mean min (SD) | 5.0 (1.3) | 5.9 (1.3) | <0.001 | 5.5 (1.2) | 5.9 (1.3) | 0.03 |
Vigorous, mean min (SD) | 5.9 (2.8) | 7.2 (2.7) | <0.001 | 7.4 (2.5) | 7.0 (2.5) | 0.30 |
MVPA, mean min (SD) | 10.9 (3.4) | 13.1 (3.2) | <0.001 | 12.9 (2.9) | 13.0 (2.9) | 0.81 |
Steps, mean (SD) | 1493 (423) | 1746 (353) | <0.001 | 1725 (333) | 1676 (309) | 0.30 |
counts/min, mean (SD) | 1529 (514) | 1837 (492) | <0.001 | 1768 (434) | 1759 (433) | 0.88 |
between intervention and control group were not significant (all p ≥ 0.22). Girls were significantly less active during PE at baseline than boys according to all variables (all p ≤ 0.001, intervention and control group together). Sex differences were still present at follow-up for some variables, however they were less pronounced in the in- tervention group.
Overall, there was a relative increase of 12% in MVPA in the intervention group while there was no change in the control group.
Furthermore, children in the lowest tertile according to MVPA during PE at baseline were compared to those in the highest tertile (
Immediately after the Y + S Kids training course, all 41 course participants were satisfied with course content,
. Physical activity time during PE lessons at baseline and follow-up, by group, by activity at baseline
Baseline | Follow-up | p | Baseline | Follow-up | p | |
---|---|---|---|---|---|---|
Most inactive third at baseline | ||||||
Intervention group (n = 86) | Control group (n = 151) | |||||
Sedentary, mean min (SD) | 19.2 (3.7) | 14.3 (2.8) | <0.001 | 17.6 (4.0) | 15.1 (3.8) | <0.001 |
Moderate, mean min (SD) | 4.2 (0.9) | 5.9 (1.2) | <0.001 | 5.2 (1.2) | 6.0 (1.4) | 0.001 |
Vigorous, mean min (SD) | 3.8 (1.1) | 6.6 (2.1) | <0.001 | 5.4 (1.4) | 6.9 (2.9) | <0.001 |
MVPA, mean min (SD) | 8.0 (1.4) | 12.5 (2.7) | <0.001 | 10.6 (1.7) | 12.9 (3.5) | <0.001 |
Steps, mean (SD) | 1130 (281) | 1712 (332) | <0.001 | 1524 (258) | 1684 (390) | 0.01 |
counts/min, mean (SD) | 1126 (181) | 1687 (364) | <0.001 | 1456 (264) | 1737 (498) | <0.001 |
Most active third at baseline | ||||||
Intervention group (n = 42) | Control group (n = 79) | |||||
Sedentary, mean min (SD) | 10.6 (2.8) | 11.7 (3.7) | 0.15 | 11.8 (2.5) | 13.5 (3.6) | <0.001 |
Moderate, mean min (SD) | 7.0 (1.4) | 6.4 (1.1) | 0.03 | 7.2 (1.5) | 6.4 (1.2) | <0.001 |
Vigorous, mean min (SD) | 10.1 (2.2) | 9.9 (2.9) | 0.75 | 11.0 (2.3) | 9.4 (3.1) | <0.001 |
MVPA, mean min (SD) | 17.1 (2.0) | 16.3 (3.1) | 0.18 | 18.2 (2.0) | 15.8 (3.5) | <0.001 |
Steps, mean (SD) | 1967 (471) | 2002 (351) | 0.72 | 2236 (344) | 1871 (310) | <0.001 |
counts/min, mean (SD) | 2332 (360) | 2300 (502) | 0.70 | 2392 (370) | 2143 (555) | 0.001 |
. Results of the mixed linear models, by sex and activity level at baseline
All (N = 237) | Boys (N = 121) | Girls (N = 116) | Most inactive third (N = 78) | Most active third (N = 80) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
coeffa | pb | pc | coeffa | pb | pc | coeffa | pb | pc | coeffa | pb | pc | coeffa | pb | pc | |
Sedentary time | −1.62 | 0.005 | 0.22 | −0.29 | 0.75 | 0.87 | −2.82 | <0.001 | 0.04 | −2.26 | 0.02 | 0.12 | −0.72 | 0.38 | 0.65 |
Light activities | 0.01 | 0.98 | 0.99 | −0.75 | 0.20 | 0.45 | 0.70 | 0.16 | 0.40 | 0.15 | 0.86 | 0.91 | −0.96 | 0.12 | 0.28 |
Moderate activities | 0.30 | 0.21 | 0.53 | 0.15 | 0.66 | 0.81 | 0.37 | 0.24 | 0.49 | 0.85 | 0.02 | 0.07 | 0.33 | 0.30 | 0.58 |
Vigorous activities | 1.31 | 0.001 | 0.08 | 0.89 | 0.16 | 0.36 | 1.75 | 0.001 | 0.03 | 1.26 | 0.055 | 0.12 | 1.36 | 0.05 | 0.08 |
MVPA | 1.61 | 0.001 | 0.13 | 1.03 | 0.19 | 0.48 | 2.12 | 0.001 | 0.06 | 2.11 | 0.01 | 0.06 | 1.68 | 0.02 | 0.12 |
Steps | 327.02 | <0.001 | 0.056 | 370.90 | 0.001 | 0.09 | 277.13 | 0.001 | 0.11 | 416.56 | <0.001 | 0.03 | 388.48 | <0.001 | 0.01 |
counts/min | 230.08 | 0.001 | 0.09 | 144.13 | 0.16 | 0.40 | 310.91 | 0.001 | 0.04 | 277.57 | 0.01 | 0.06 | 218.11 | 0.07 | 0.19 |
aCoefficient for interaction term “time × group”. bp-values for models without taking into account clustering within classes. cp-values for models tak- ing into account clustering within classes, Note: all models were adjusted for sex, age, education of parents, migration background of child and over- weight.
56% were even completely satisfied. 93% reported that they would be able and 7% that they would be partly able to use what they had learnt in the course in practice. 90% of course participants were planning to offer a Y + S course. Overall, the general comments on the teachers’ training course were positive, with some reservations about the administrational requirements of the program.
The six teachers of the intervention classes still rated their training course very positive five months later. They especially appreciated its practice-orientated format and they reported to frequently use the course material. Again, two of the six intervention teachers still mentioned their reservations about the administrative require- ments.
There was a small but statistically significant increase in activity time and a decrease in sedentary time during PE in the intervention group between baseline and follow-up while there were no significant changes in the con- trol group, indicating that there was an intervention effect of the Y + S Kids teachers’ training course in regular PE lessons. In particular, girls and the least active children at baseline profited most with highest increases in ac- tivity time in the intervention group. These results suggest that also less extensive school-based interventions that are feasible for wide implementation have the potential to improve the quality of PE lessons as indicated by activity time of children. Y + S Kids is already widely implemented in Switzerland and is therefore a good ex- ample of a feasible and effective national program. Moreover, the high acceptance of the teachers’ training course supports the feasibility of wide implementation.
Even though the PE lessons are the same for boys and girls, girls were less active at baseline than boys. The intervention was able to decrease this gender difference perhaps in the way that activities were performed that are also attractive for girls.
The share of MVPA during PE in our study (27% in intervention, 31.8% in control group at baseline) was lower than the average of 37% derived from other studies included in a review [
The analyses revealed that the increase in activity time in the intervention group was mainly due to changes in vigorous-intensity activities, as reported elsewhere [
For the most inactive third at baseline, increases in activity time were also observed in the control group, however these were smaller than in the intervention group. Furthermore, while the most active children in the intervention group maintained activity time, this group of children in the control group significantly decreased theirs. This may be interpreted as “regression to the mean” [
The intraclass correlation coefficients were between 0.1 and 0.3 for most outcome variables (data not shown) and therefore in the range assumed when doing the sample size calculations. The fact that several of the associa- tions in the mixed linear models (
As the proportion of time spent in physical activity also depends on the cut points as described above, it is theoretically possible that the choice of cut points may also have affected the observed differences in physical activity over time. However, it is unlikely that the effects of different cut points on activity time are differential with respect to intervention and control group and would so alter the net intervention effect.
Other studies have reported positive effects of interventions on physical activity time during PE [
The strength of our study is the objective assessment of physical activity, the high participation rate at the level of children, the standardised intervention for all teachers of the intervention class, and the investigation of a widely implemented intervention. The study design (quasi-experimental rather than randomised) may be re- garded as a limitation, however it was not feasible to randomly assign participating teachers to the intervention which also included offering an additional PE lesson (Y + S Kids course) for their class during one year. The follow-up was relatively short, but we assumed that effects on the quality of PE should be observable soon after the intervention. Due to organisational issues, the study could not be blinded. The participation rate at the school level (26.9%) may seem low; however, the main reasons for non-participation were other priorities of the schools and not a general lack of interest. A similar selection mechanism regarding participation in the Y + S Kids program is likely to also take place outside this study. Therefore, the results of our study should be gener- alisable to teachers and classes participating in Y + S Kids not in the context of this study. We could only reach about 90% of the target sample size of 260 children; moreover, the group allocation was unbalanced (86 in in- tervention group, 151 in control group). This may be a reason why the mixed linear models reached significance only in some sub groups and for specific physical activity variables.
Ideally, further research should include a randomised study design, assess also other quality indicators of PE, look at changes in overall physical activity in a larger sample and also integrate long-term maintenance of physical activity. Whether a specific focus of training courses aiming at an increase in activity time during PE would bring further improvements in physical activity remains to be explored.
In conclusion, this study indicates that a short two-day teachers’ training course for classroom teachers aiming at increasing didactical and organisational skills in the context of a nation-wide available physical activity and sport program can have subtle positive effects on quality of PE assessed as physical activity time during PE classes, particularly in girls and the least active children. Even though the absolute increase in the range of 1.5 minutes in all intervention children and 4.5 minutes in those inactive at baseline is quite small, it is in line with results reported in other studies [
This study was funded by the Swiss Research Concept Sports and Physical Activity 2008-2011 (grant 11-05), the Swiss Council for Accident Prevention, Migros culture percentage, the Swiss Foundation for the Health of Children and Adolescents, and the Swiss Association of Sports Medicine.
We thank Martin Jeker, former head of the Y + S program for early input concerning the intervention hypo- thesis; Christian Koch and Christian Müller, Canton of Aargau, for their support regarding recruitment and for the organization of the teachers’ training course; Nadine Eberle, Sabrina Eibisch, Michèle Geissbühler, Theo Härry, Pascal Hostettler, Melanie Keller, Mirco Trachsel and Claudia Wintersohle for their assistance in the data collection; Burkhardt Seifert for statistical advice. And we thank all teachers, headmasters, children and parents for their participation in the study.
This study was funded by the Swiss Research Concept Sports and Physical Activity 2008-2011 (grant 11-05), the Swiss Council for Accident Prevention, Migros culture percentage, the Swiss Foundation for the Health of Children and Adolescents, and the Swiss Association of Sports Medicine.