2026-06-17T20:30:11Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/112122026-01-14T01:05:42Zcom_10259.4_2551com_10259_5086com_10259_2604col_10259.4_2552

Howard, Kristen R. Prado‐Nóvoa, Olalla Zorrilla Revilla, Guillermo Laskaridou, Eleni Reid, Glen R. Marinik, Elaina L. Stamatiou, Marina Hambly, Catherine Davy, Brenda M. Speakman, John R. Davy, Kevin P. 2026-01-13T13:29:38Z 2026-01-13T13:29:38Z 2025-10 0027-8424 https://hdl.handle.net/10259/11212 10.1073/pnas.2519626122 1091-6490 The prevailing linear model of physical activity (PA) and total energy expenditure (TEE) has been challenged by models that predict an upper limit of TEE linked to a compensatory reduction elsewhere in the energy budget in response to increased PA. We determined the equation of best fit between PA and TEE and explored relationships between PA and behavioral and physiological compensation. Using linear and nonlinear modeling, we observed a positive linear relationship between PA and TEE either without or after adjustment for fat-free mass (R2= 0.3492, TEE = 0.00685*PA + 7.124: R2=0.3667, TEE_ADJ(FFM) = 0.00511*PA + 8.598). Higher PA was associated with lower sedentary time (R2= 0.7207, %SPA= −0.0211*X + 91.261). There was no association between PA, TEE, or resting metabolic rate and adjusted biomarkers of immune, reproductive, or thyroid function after Bonferroni correction. The findings of this observational study do not support the constrained/compensated model but affirm the conventional additive relationship between PA and TEE across a broad range of PA levels. K.R.H. is funded by a Virginia Tech Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Fellowship, O.P.-N. is funded by a Virginia Tech Presidential Postdoctoral Fellowship, and G.Z.-R. is funded by Next Generation European Union funds Margarita Salas Postdoctoral Fellowship. application/pdf eng National Academy of Sciences Proceedings of the National Academy of Sciences. 2025, V. 122, n. 43, p. e2519626122 https://doi.org/10.1073/pnas.2519626122 Attribution-NonCommercial-NoDerivatives 4.0 Internacional http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Physical activity Energy expenditure Doubly-labelled water Constraint Compensation Fisiología humana Ejercicio físico Metabolismo energético Human physiology Exercise Energy metabolism Physical activity is directly associated with total energy expenditure without evidence of constraint or compensation info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Proceedings of the National Academy of Sciences 122 43 e2519626122