Exercise as it relates to Disease/The effect of exercise on mental health outcomes of pre- and early-school-aged children

This is a critique of the article Exercise effects on mental health of preschool children, published in the Anales de Psicología/Annals of Psychology.

What Is The Background To This Research?
The positive effects of physical exercise on mental health are well documented in prior research. However these results are based predominantly on research examining an adult population, while children of different ages were neglected.

Meta-analysis research conducted in the last several years on the population of children and adolescents indicates a wide range of obtained results. These results range from those indicating a medium to strong correlation between engagement in physical activity and the mental health of young people, especially when anxiety and depression are concerned, to those which indicate that the correlation is weak, if there is any at all.

This paper deals with problem behaviour in terms of externalising and internalising behaviour, which is classification common in children’s psychology and psychiatry. The externalising spectrum incorporates a variety of disinhibited or externally focused behavioural symptoms including aggression; conduct problems, delinquent behaviour, oppositionality, hyperactivity, and attention problems. The internalising spectrum includes a variety of over-inhibited or internally focused symptoms including anxiety, fear, sadness/depression, social withdrawal, and somatic complaints. Studies of children often find the two positively correlated to one another. In this study, it was hypothesised that children from intervention group would express less externalising and internalising behaviour in comparison to children from the control group after 2.5-year period.

Where Is The Research From?
This study originates from the Faculty of Sport and Physical Education, at the University of Novi Sad in Serbia. The first author, Tatjana Tubić is a full professor of Psychology at the university. Tubić specialises in Sport Psychology and Teacher Education. The second, Višnja Đorđić is an Associate Professor at the University, who specialises in the areas of Physical Education, Gender Issues in Sport and Public Health. Per ResearchGate, Đorđić and Tubić have 74 and 34 items of which they have contributed, respectively. They both have an extensive history of research in the area.

What Kind Of Research Was This?
The study’s purpose was to identify effects of 2.5-year movement program on mental health of preschool children, as measured by reduction in symptoms of externalising and internalising behaviour. The trial was a cohort study that consisted of 184 children (both male and female) with 53 of the children being assigned to the intervention group, being compared to 167 other children, who were randomly chosen and tested. This ‘comparison’ or more commonly ‘control’ group participated in physical exercise only through their regular activities within the preschool curriculum. All children in the sample were enrolled in kindergartens in Novi Sad. It is important to note that preschool children in Serbia are 5 to 7 years of age.

A voluntary response sampling dictated assignment to the intervention group. Parents of the children would have to administer and maintain the 2.5-year physical activity intervention. While finding volunteers is often a relatively fast and affordable way to gather participants, it is highly susceptible to bias. This is because researchers can make little effort to control sample composition. The people who do volunteer may have more favourable characteristics that may affect the validity and reliability of the experiment. However, whether this occurs is dictated by this actual study being done.

Cohort studies look at two or more groups of people. They can be prospective (forward-looking) or retrospective (backward-looking). Prospective studies are planned in advance and carried out over a future period of time. From the researchers point of view the study was observational, as they did not administer the intervention, however just measured the results at specific intervals. The Aberrant Behaviour Questionnaire (ABC), containing 16 items (dependent variables), was the measurement tool utilised to examine the symptoms of externalising and internalising behaviour. The ABC is a 58-item questionnaire for caregivers, that is designed to assess the presence and severity of various problem behaviours commonly observed in individuals diagnosed with intellectual development disorders. Metric characteristics of this instrument were verified on the Serbian sample of 1165 children aged between 4 and 7.

In order to deeper insight into the changes of certain types of problem behaviour under the influence of the intervention movement program, the statistical significance of the differences within intervention group and the control group were analysed using a Wilcoxon Test. There were a few limitations of this study that were noted by the authors. Firstly the number of children who participated in the intervention was significantly reduced from the initial to final measurement, which doubtlessly limits the possibility of generalising the results. All of the children involved were white, and were from the territory of Novi Sad, but the groups were not matched according to socioeconomic (S.E.) status. It was theorised that those who remained may have been those families from a higher S.E. status, as the parents financed the intervention movement program themselves. Also, as the measuring instrument used was administered by the parents of the children, there is a certain level of subjectivity that cannot be eliminated.

What Were The Basic Results?
The basic results indicated that physical exercise had an influence on the reduction of problem behaviour. When looked at holistically, all indicators of externalising behaviour, without any exception, decreased in the intervention group of children. The regularity of changes was seen from the initial, through transitive to final measurement. It is important to note, that not only the tendency of decreasing of this form of behaviour measured by the appropriate indicators can be noticed, but also decreasing within much wider limits, when compared to the control group of children. For internalising behaviours, it could be noted that all variables in the final measurement had lower scores than those in the initial, but in this case, only 3 of them decrease monotonously.

Even though the results were very noticeable, the researchers could only speak on the tendencies of reducing problem behaviour through physical exercise, as there were no statistically significant differences between the intervention and control groups at the observed ages of children, save for sporadic ones. This means that the research hypothesis could only be partially confirmed.

What Conclusions Can We Take From This Research?
Based on the results of this study and those that came before, it could be concluded that sustained physical activity can help to reduce the symptoms of externalising and internalising behaviour. While the intervention was not successful in reducing all variables measured, across all groups, there remains substantial evidence to support to research hypothesis.

The results of an even longer-term exposure to maintained physical activity are seemingly yet to be documented, in my own research. It would be a potential avenue of further study on the topic.

Practical Advice
Children who exhibit problem behaviours, such as those in focus in the study, would likely find benefit from maintaining extra-curricular physical activity during their formative child and teen years. However, exercise is not the only form of treatment per se, which could be employed, especially when family S.E. status and the particular child’s tendencies may not allow for, or be suited to this type of treatment, respectively.

Further Information/Resources
Raising Children Network

Kids Help Line