@article{Limpens_Hofman_Voortman_2021, title={Reallocations of movement behaviors and body composition in middle aged and elderly: Oral Presentation B12.4}, volume={14}, url={https://hfjc.library.ubc.ca/index.php/HFJC/article/view/571}, DOI={10.14288/hfjc.v14i3.571}, abstractNote={<p>sarcopenic obesity. Previous studies suggested that body composition can be affected by physical activity and sedentary behavior, however, they did not account for the dependency of these activity domains and sleep, being bound within the 24-hour day. Purpose: This study aimed to investigate the associations between reallocations of time among time-use movement behaviors and detailed body composition measurements in middle-aged and older adults. Methods: We included 1,874 participants (mean age 71.5±9.3 years, 50.2% women) from the large prospective population-based Rotterdam Study. We collected up to 7 days 24-hour accelerometer data (GeneActiv) to estimate sleep, sedentary behavior (SB), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA). Body composition was measured using dual-energy X-ray absorptiometry (DXA) from which we calculated: body mass index (BMI), total body fat percentage (%BF), fat mass index (FMI) and fat-free mass index (FFMI). Results: MVPA was associated with lower BMI, mainly explained by a lower FMI, irrespective of whether it was replaced with 30 minutes of sleep (B:-0.72, 95%-confidence interval (CI) -0.98;-0.46), sedentary (B:-0.82, 95%-CI -1.08;-0.56), or LPA (B:-0.76, 95%-CI -1.27;-0.25). More MVPA was to a smaller extent also associated with a lower FFMI, but overall with a lower %BF. Conclusions: The composition of movement behaviors is associated with body composition in middle-aged and elderly. Increased MVPA at the expense of other physical behavior measures was associated with lower BMI, which was explained mainly by less body fat. Funding: Horizon2020.</p>}, number={3}, journal={The Health & Fitness Journal of Canada}, author={Limpens, Marlou and Hofman, Amy and Voortman, Trudy}, year={2021}, month={Sep.} }