Physical activity is directly associated with total energy expenditure without evidence of constraint or compensation

K Kristen R. Howard (Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech) O Olalla Prado-Nóvoa (Department of Human Nutrition Foods and Exercise, Human Integrative Physiology Laboratory, College of Agriculture and Life Sciences, Virginia Tech) G Guillermo Zorrilla-Revilla (Laboratorio de Evolución Humana, Departamento de Historia, Geografía y Comunicación, Universidad de Burgos Laboratorio de Evolución Humana, Departamento de Historia) E Eleni Laskaridou (Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech) G Glen R. Reid (Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech) E Elaina L. Marinik (Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech) M Marina Stamatiou (Institute of Biological and Environmental Sciences, University of Aberdeen) C Catherine Hambly (Institute of Biological and Environmental Sciences, University of Aberdeen) B Brenda M. Davy (Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech) J John R. Speakman (Institute of Biological and Environmental Sciences, University of Aberdeen) K Kevin P. Davy (Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech)

Abstract

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 (R 2 = 0.3492, TEE = 0.00685*PA + 7.124: R 2 =0.3667, TEE_ADJ(FFM) = 0.00511*PA + 8.598). Higher PA was associated with lower sedentary time (R 2 = 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.

Article Details

Volume / Issue Vol. 122, Issue 43
Published October 28, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (11)

K

Kristen R. Howard

Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech

O

Olalla Prado-Nóvoa

Department of Human Nutrition Foods and Exercise, Human Integrative Physiology Laboratory, College of Agriculture and Life Sciences, Virginia Tech

G

Guillermo Zorrilla-Revilla

Laboratorio de Evolución Humana, Departamento de Historia, Geografía y Comunicación, Universidad de Burgos Laboratorio de Evolución Humana, Departamento de Historia

E

Eleni Laskaridou

Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech

G

Glen R. Reid

Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech

E

Elaina L. Marinik

Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech

M

Marina Stamatiou

Institute of Biological and Environmental Sciences, University of Aberdeen

C

Catherine Hambly

Institute of Biological and Environmental Sciences, University of Aberdeen

B

Brenda M. Davy

Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech

J

John R. Speakman

Institute of Biological and Environmental Sciences, University of Aberdeen

K

Kevin P. Davy

Translational Obesity Research Interdisciplinary Graduate Education Predoctoral Program, Virginia Tech