The results of this study indicate that PL is associated with important aspects of children’s well-being. First, we observed a positive moderate association between PL and physical well-being which was partly mediated by MVPA. The observed association between MVPA and physical well-being was positive and moderate indicating that PL is important for children’s physical well-being and that some of this relationship works through the level of PA. It is worth noticing that some of the items in the latent construct physical well-being are related to being active in general (e.g. “Has your child been physically active?” and “Has your child felt full of energy?”) and to cardiorespiratory fitness (i.e. “Has your child been able to run well?”). It is, therefore, perhaps not surprising that MVPA is associated with this construct of physical well-being. A high similar correlation between the KIDSCREEN physical well-being subdomain and objectively measured MVPA were observed in a similar sample (68).
Secondly, we observed a beneficial association between PL and all aspects of psychosocial well-being, with β-values ranging from .21 to − .32, and with no mediating role of MVPA. These results are in line with a study among 222 Canadian schoolchildren (mean age: 10.7 ± 1.0 years) where the authors observed a direct effect from PL to Health-Related Quality of Life (HRQoL), but no effect of MVPA on HRQoL, and no mediating effect of MVPA (24). The latent construct HRQoL was measured with four subdomains of which three are comparable to the aspects of psychosocial well-being measured with the SDQ. The fourth subdomain corresponds to the physical well-being subdomain of KIDSCREEN.
We observed a detrimental association between MVPA and externalizing symptoms, which has been found in similar samples (69, 70). This association may be explained by the nature of externalizing and especially hyperactive behaviour, resulting in higher levels of accelerometer measured daily total PA. Further, we observed a very weak detrimental association between MVPA and prosocial behaviour (β = − .05) and found no associations between MVPA and the remaining aspects of psychosocial well-being or the total difficulties score. Other studies have similarly found no association between MVPA and the SDQ measured total difficulties score (69–72). Contrary to our results, these studies observed a beneficial association between MVPA and the internalizing subscale. A reason why we didn’t see this association in our study could be that we included PL in our models and/or that such relationships vary among population groups.
Together, the non-significant or detrimental associations between MVPA and different aspects of psychosocial well-being, and the beneficial association between PL and psychosocial well-being with or without controlling for MVPA in the model indicate that PL may have a positive impact on children’s general well-being. However, studies with an experimental design are needed to confirm this.
In general, it is difficult to compare results across studies investigating psychosocial well-being, as there is no universal definition to the term. This is perhaps a reason why systematic reviews and meta-analyses find mixed results of PA interventions on well-being (28, 73). A review focusing on objectively measured levels of PA and the relation to different aspects of well-being in children and youth found some support for beneficial associations between MVPA and health indicators such as quality of life, pro-social behaviour, and psychological distress (6). A large review of reviews examined the relationships between PA, depression, and anxiety in children and adolescents. The authors concluded that observational evidence indicates a beneficial association between PA and depression ranging from null to small, and very small to moderate effect sizes for PA on anxiety (3). In this study, we only observed associations from PA to two aspects of psychosocial well-being. In our study, the construct psychosocial well-being is based on a definition and measure of psychological and social well-being as function in the everyday life measured by problem and well-functioning behaviour, and thus, it is problematic to compare it to constructs like depression and anxiety.
A reason why we observed an association between PL and psychosocial well-being, independent of PA could be that the affective elements of PL, motivation, and confidence, have an impact beyond PA contexts as described in Vallerands hierarchical principle of motivation (74). As described in self-determination theory (75), well-being and intrinsic motivation are interlinked such that when the basic psychological needs (feeling of autonomy, confidence, and belonging) are satisfied the individual will experience well-being in an activity which is necessary for sustained intrinsic motivation for the activity (76). According to the theory of PL (16), when an individual’s PL is positively developed in a movement context, all of the elements are positively stimulated including the affective elements motivation and confidence. Thus, children with greater PL score increase the possibility to have positive experiences in PAs (16), and thus increases the possibility to feel well-being in PA’s which is a part of their general well-being. It has been suggested that the effects of motivation and healthy functioning/well-being can transfer across related contexts (77). Thus, children with greater PL will be more likely to feel well during PA’s and the effect may cross to other contexts of the child’s everyday life.
Even though the models only explained a small part of the variance in the outcomes for psychosocial well-being (5–12%), the results are relevant, as PL seems important for children’s psychosocial well-being beyond its association to MVPA and because both well-being and development of life competencies are the core purpose of schools in many countries.
Implications for practice, policy, and research
First, findings from this study respond to the call for more research on the link between PL and physical, psychological, and social health, and provide more support for the assumption that PL is a determinant of health. Second, the null finding of MVPA on aspects of psychosocial well-being along with the positive relation to PL supports the idea that helping children develop their PL is more beneficial for general long-term health than a narrow focus on increasing their levels of PA. This speaks to a need of shifting the focus from the amount and intensity of PA to quality and enjoyment when encouraging children to move.
Strengths and limitations
There are some strengths and limitations connected to the design and methods of this study. The amount of missing data should be considered a limitation. The highest amount of missing data was in the outcome variables about well-being (68% response rate). This might be due to that these questionnaires were sent to the parents on the last day of the data collection period, however, the response rate for the questionnaire sent on the first day was only a little better (78%). From the dropout analysis (Table 2) it was evident that the participants with missing data in the outcome variables scored 7.5% lower in PL but did not differ in MVPA. Missing data in the PL elements were mostly due to children not attending school on one or both test days. Missing data in the PA measure were due to children removing the monitor after a few days, and to children who lost the monitor or forgot to return it. Nevertheless, for such direct measures used in this study the final sample size is rather large and should be considered a strength.
A strength of the study is the use of objective assessment of participants’ PA (43) with the use of skin-taped accelerometer mounting to reduce some of the limitations that are usually connected to this device (44). The high number of participants (73%) with valid PA data supports the strength of this method. However, when using accelerometers alone, information about context, setting, and characteristics of the activities are absent, which could be important to understand the association between PA and psychosocial well-being.
The assessment of physical and psychosocial well-being also has some limitations. Physical well-being was assessed by the subdomain of the KIDSCREEN consisting of items that are also part of the construct PA, which perhaps makes it less suitable for exploring associations to MVPA.
The SDQ questionnaire used to measure psychosocial well-being has been criticized for being less suitable to measure the variance within a normal/healthy sample. This instrument was first developed to identify children with difficulties (50), which introduces the risk of a flooring effect, and thus loss of variance, when used in a community sample. Further, the reliability values for the individual prosocial scale were below acceptable values and thus, results related to this outcome should be considered with additional caution. Nevertheless, using the subscales for analysis brings additional information in the explored relationship among PL, PA, and different aspects of psychosocial well-being.
The use of the structural equation model in the investigation of the associations must also be considered a strength, as this method of analysis, minimises selection bias by imputing missing values by maximum likelihood estimation.
The main limitation of the study is perhaps the cross-sectional design, which introduces uncertainty about the direction or causality of the association. We must consider the possibility that children that thrive in general also thrive in the context of PA’s and thus have higher motivation, confidence, motor skills, etc. Research studies with longitudinal and experimental designs are needed to inform us on the direction of the associations examined in this study.