## 4 Discussion  
To our knowledge, this study represents the first analysis of associations between meeting 24 h movement guidelines and HRQoL in a young population during the COVID-19 pandemic. Our results show a higher HRQoL score in those who met the 24 h movement guidelines in comparison to those who did not. Not meeting the 24 h movement guidelines was associated with worries, sadness, or unhappy feelings. The overall findings of our study are in accordance with the pre-pandemic results based on a sample composed from 12 countries [12], where children meeting all the three 24 h movement guidelines had greater HRQoL outcomes than children not meeting these guidelines. This observation was also shown by [PERSON] et al. (2021) [4] in their study of Australian adolescents. However, neither of these studies were performed during the COVID-19 pandemic, which could affect the results. Additionally, one pre-pandemic longitudinal study of Australian children showed that those who met with the 24 h movement guidelines scored higher in HRQoL than those who did not [5]. A recent systematic review concluded that the COVID-19 pandemic has had a negative effect on the HRQoL of children and/or adolescents [13]. In addition, [PERSON] et al. [5] pointed out the possible HRQoL consequences for children and adolescents regarding restrictions of physical activities during the COVID-19 pandemic. However, no previous  
Figure 3: Association between meeting 24 h movement guidelines and problems in different dimensions of HRQoL (Odds Ratio and Confidence Intervals). (**A**) Mobility; (**B**) Looking after myself; (**C**) Having pain or discomfort; (**D**) Doing usual activities; (**E**) Feeling worried, sad or unhappy. Adjusted for age, sex, nationality, breadwinner’s educational level, socioeconomic status, body mass index (z-score), and Mediterranean Diet. * Note: The mobility dimension did not present a high enough number of cases with problems; therefore, the analysis was not applicable (N/A). studies have examined this association. In this regard, our results that meeting the 24 h movement guidelines (despite COVID-19-related limitations) was linked to higher HRQoL and lower feelings of worries/sadness/unhappiness are novel. One possible explanation for the positive association with meeting 24 h guidelines would be their related benefits in building social connectedness, reducing screen time, enhancing self-esteem, and increasing sleep quality, which affect psychosocial health [25]. Another possible reason could be related to internet gaming disorders (as a proxy of sedentary behaviour), which directly influenced insomnia and quality of life among participants during the COVID-19 pandemic [26]. However, gaming was not specifically assessed in this study. In addition, it is possible that parenting style and home conditions influenced HRQoL[27]. Additionally, the sense of connectedness to caregivers has been pointed out by children as a moderate-to-strong predictor of negative feelings (e.g., happiness) during the COVID-19 pandemic [28]. However, parenting style, home conditions, and a sense of connectedness to caregivers were not assessed in our study. Another finding of our study was that meeting the 24 h movement guidelines was inversely related to worries/sadness/unhappy feelings. Supporting these findings, [PERSON] et al. (2021) [29] showed that the healthiest movement behaviour profile was consistently associated with better mental wellbeing among Canadian adolescents, and [PERSON] et al. (2022) [30] showed similar results in Spanish children and adolescents for psychosocial behavioural problems. There are some reasons that could explain these results; for instance, meeting 24 h movement guidelines and social and physical environmental conditions (e.g., being physically active or having access to different spaces) have been linked to better subjective wellbeing consequences during the COVID-19 pandemic [31].