Individual and combined impact of physical fitness on health-related quality of life during adolescence: DADOS Study

The bidirectional longitudinal association between health-related quality of life and academic performance in adolescents: DADOS study

PURPOSE

Although previous evidence has suggested a relationship between health-related quality of life (HRQoL) and academic performance, the directionality of this association is understudied and remains to be clarified. Thus, the primary objective of this study was to explore the bidirectional association between HRQoL and academic performance in adolescents between two timepoints with a 24-month interval. A secondary aim was to analyze whether this association varies between boys and girls.

METHODS

This is a bidirectional longitudinal analysis with 257 adolescents (13.9 ± 0.3 years at baseline) from the DADOS study. HRQoL was measured using the KIDSCREEN-10 questionnaire. Academic performance was assessed through academic grades and the Spanish version of the Science Research Associates Test of Educational Ability.

RESULTS

Cross-lagged analyses revealed that HRQoL at baseline was not associated with academic performance 24 months later, while all the academic grades and the overall score of academic abilities at baseline were positively associated with HRQoL at follow-up in adolescents. Results of the stratified analyses by sex were largely similar. Specifically, in girls, math, language, physical education, and grade point average at baseline were positively associated with HRQoL 24 months later, while in boys, all the academic grades indicators (except physical education), numeric ability, and the overall score of academic abilities at baseline were positively associated with HRQoL at follow-up.

CONCLUSION

These findings suggest that academic performance in early adolescence may predict HRQoL 24 months later. Health and education professionals could benefit from collaborating to achieve both improved academic performance and HRQoL in youth.

The Mediating Role of the Muscle Quality Index in the Relation of Screen Time and Abdominal Obesity with Health-Related Quality of Life in Chilean Schoolchildren

Screen time (ST) and abdominal obesity have a negative effect on health-related quality of life (HRQoL). However, there is little information regarding the mediating role of the muscle quality index (MQI) in these relationships. The aim of the present study was to investigate the association between HRQoL, physical status (i.e., anthropometrics and fitness), lifestyle (i.e., ST and physical activity), and the MQI, and then to determine the potential mediating role of the MQI in the relation of ST and abdominal obesity with HRQoL in Chilean schoolchildren. The cross-sectional study included 750 schoolchildren (girls, n = 332 and boys, n = 418) aged between 10 and 14 years (11.73 ± 1.08 y). MQI, lifestyle, fitness parameters, waist-to-height ratio (WtHR) and HRQoL were measured. HRQoL presented a significant correlation with WtHR (r: -0.19), VO2_max (r: 0.20), physical activity after school (r: 0.26), ST (r: -0.26) and MQI (r: 0.15). According to MQI, the high-MQI group reported higher HRQoL than the low-MQI group (low MQI: 36.10 ± 3.63 vs. high MQI: 37.43 ± 4.00, p < 0.001). In the mediation model, ST and abdominal obesity were negatively linked to HRQoL; the indirect effect confirmed that MQI is a partial mediator in the relation between ST and HRQoL (indirect effect = -0.04; SE = 0.02; 95% CI: -0.09, -0.01) and in the relation between abdominal obesity and HRQoL (indirect effect = -1.81; SE = 0.83; 95% CI: -3.41, -0.40). In conclusion, MQI is related to better HRQoL in schoolchildren, and the negative relation of ST and abdominal obesity with HRQoL is mediated by MQI.

Association of modifiable factors with the development of physical fitness of Austrian primary school children: A 4-year longitudinal study

Physical fitness (PF) shows favourable associations with several health indicators in children. Children's PF depends on a variety of non-modifiable (e.g., sex and age) and modifiable factors (e.g., weight status and sports participation). The aim of this study was to evaluate the impact of modifiable and non-modifiable factors on the development of PF during the 4 years of primary school. A longitudinal study was carried out with 265 children. PF was assessed using the German Motor Performance Test 6-18, whereas modifiable and non-modifiable factors with parent's and children's questionnaires. Total PF z-score increased by 1.4 standard deviations from 1^st to 4^th year and raw values of subtests improved by an average of about 40%. The variables "parents' physical activity", "never being overweight", "sports club participation", and "playing outside" were positively associated with PF development. The present study highlights that a variety of modifiable factors, both from children and their parents, are significantly associated with the development of children's PF during primary education. Interventions should not only focus on direct actions, such as proposing specific exercise programs, but also aim at increasing parents' awareness of their role model function in endorsing their children's healthy active lifestyle, especially at early ages.