Pia Skovdahl
Doctoral Student
Department of Food and Nutrition and Sport ScienceAbout Pia Skovdahl
Pia Skovdahl is a doctoral candidate at the Department of Food and Nutrition, and Sport Science at the University of Gothenburg. She holds both a bachelor’s and a master’s degree in Sport Science from the same university. In her ongoing PhD project, she works with methodological development of accelerometer-based measurements for use in clinical populations – with a particular focus on assessing physical activity levels in children and adolescents with congenital heart disease (CHD). The project is an interdisciplinary collaboration between the university hospitals in Gothenburg, Lund, and Stockholm, as well as the Centre for Health and Performance at the University of Gothenburg.
Pia has a strong passion for children’s physical activity, wellbeing, and quality of life. She is dedicated to bridging the gap between research and practice, aiming to ensure that new knowledge is applied in ways that benefit children, families, and clinicians in everyday life.
Her doctoral thesis explores physical activity among children and adolescents with congenital heart disease (CHD), while simultaneously developing more precise methods for measuring activity using accelerometry. The work addresses a key knowledge gap in current physical activity research: while we know that physical activity is crucial for children’s physical and mental health, reliable methods to accurately measure how active children are—both those with CHD compared to healthy peers, and children in general—have been lacking.
The thesis comprises four studies that together form a methodological development process—from identifying the problem to applying new solutions in clinical practice:
Study 1 (Skovdahl et al., 2021): A review that revealed large discrepancies in previous research on activity levels among children with congenital heart defects, mainly due to the use of different measurement methods and accelerometer processing settings, leading to conflicting results.
Study 2 (Skovdahl et al., 2025): Examined the relationship between accelerometer outputs (filters) and oxygen consumption (VO₂) metrics, and to what extent these could be normalized across age and body size (ranging from 4 years to adulthood), to allow a single calibration regression line for absolute physical activity intensity. This resulted in a new age-independent calibration method explaining over 92% of the variance, with minimal remaining between-group and inter-individual variation—representing an important methodological breakthrough.
Study 3 (manuscript in preparation): Investigates how different accelerometer processing settings influence associations between physical activity and health outcomes, thereby contributing to the establishment of a methodological standard for future research.
Study 4 (manuscript in preparation): Applies the newly developed methods in a national study of children and adolescents with CHD, comparing their activity levels to age-, sex-, and region-matched healthy controls—with greater precision than previously possible.
Through this work, a complete methodological pipeline for measuring physical activity is developed—from problem identification to clinical application. The thesis thus contributes both methodologically, by standardizing physical activity measurement in children, and clinically, by providing new and more reliable insights into activity patterns among children and adolescents with congenital heart disease