Assessing Children's Growth and Motor Development after the COVID-19 Pandemic: Insights from the REACT Project

In this special issue of the American Journal of Human Biology, Guest Editors Sara Pereira, José Maia, and Peter Katzmarzyk, along with their research collaborators, summarize the initial findings from the REACT Project (“Return-to-Action after the COVID-19 Pandemic”). The REACT Project is a longitudinal study of growth, motor development, and health behaviors carried out among school children ages 6–10 years from Matosinhos, northern Portugal. The primary objectives of this research were to: (1) evaluate children's growth and motor development following the COVID-19 pandemic, and (2) track the developmental trajectories of fundamental movement skills (FMS) using a novel technology, the Meu Educativo® app, in their physical education classes.

This is the first special issue of the AJHB to provide findings from a single, pandemic-initiated research project. The eight papers in this issue offer an example of the impressive work being done by human biologists to explore the short and longer-term influences of the pandemic on human health and well-being. The REACT Project's focus on evaluating and promoting healthy patterns of physical growth, activity, and motor development in the wake of the pandemic is particularly salient given the importance of these early-life factors for shaping adult health outcomes and disease risks.

Sara Pereira et al. (2024b) open this special issue by providing an overview of the objectives, research design, and methodologies used in the REACT study. The thoughtful and rigorous protocol for the study is allowing the researchers to explore the influence of diverse family, school, and neighborhood factors in shaping children's physical growth, movement skills, fitness, and health behaviors. Such rich insights offer to provide valuable information to both parents and educators on how to effectively promote physical activity and healthy growth and development among school-aged children.

Papers by Donald Hedeker et al. (2024) and Fernando Garbeloto et al. (2024b) highlight the novel analytic and statistical approaches employed in the REACT research project. Hedeker and colleagues offer a detailed and accessible discussion of the utility of multilevel ordinal logistic models for evaluating longitudinal changes in motor development. Garbeloto and colleagues document the utility and reliability of the Meu Educativo® application for assessing children's FMS levels. This paper showcases how this new tool can be effectively used by researchers, educators, and coaches interested in evaluating patterns of motor development during childhood.

Papers by Sara Pereira et al. (2024a) and José Maia et al. (2024) employ multivariate, multilevel approaches to explore the influence of both individual and school factors in shaping children's body mass indexes (BMI), fitness levels, and motor performance. Pereira and colleagues find that greater cardiorespiratory fitness is associated with significantly lower BMIs in this sample, with most of the variation in both of these measures being explained by child-level variables. Similarly, Maia and colleagues show that the majority of variation in FMS is determined by child-level variables. However, they also document that school programs matter, arguing for the establishment of supportive learning environments that address socioeconomic inequalities and help to establish equitable spaces allowing children to achieve their full potential in fitness and motor development.

Priscyla Praxedes et al. (2024) consider the influence of multiple factors (obesity, movement behavior and socioeconomic status [SES]) on the development of FMS among the children of the REACT sample. They demonstrate that obese children and those with more sedentary daily activities have lower FMS scores, whereas the SES of a child's family was not associated with FMS levels. These findings highlight the importance of daily physical activity for enhancing motor development among children of all social and economic backgrounds.

Fernando Garbeloto et al. (2024a) examine the association between moderate-to-vigorous physical activity (MVPA) and FMS levels in the REACT sample. They find that children with higher FMS scores tend to be more physically active and are more likely to reach the WHO's target of 60 minutes of MVPA per day (Bull et al., 2020; WHO, 2018).

Jean-Philippe Chaput et al. (2024) conclude this special issue by exploring the potential influence of sleep on FMS levels. While the influence of sleep on neurodevelopment has been widely studied (e.g., Page et al., 2021; Short et al. 2018), research on the relationship between sleep and motor development is more limited (Chaput et al., 2017). Intriguingly, in this study Chaput and colleagues do not find a relationship between sleep and FMS performance, suggesting that sleep is not a good correlate of motor proficiency.

I sincerely thank Sara Pereira, José Maia, Peter Katzmarzyk, and all of the authors for their thoughtful and timely contributions to this special issue. I look forward to the important findings still to come from the REACT research. The AJHB will continue to be a leading venue for publishing original research, reviews, and commentary addressing the diverse health consequences of the COVID-19 pandemic (Leonard, 2020).