No evidence for metabolic adaptation during exercise-related energy compensation

• Published in: iScience 2024-06, Vol.27 (6), p.109842, Article 109842
• Main Authors: Flanagan, E.W., Sanchez-Delgado, G., Martin, C.K., Ravussin, E., Pontzer, H., Redman, L.M.
• Format: Article
• Language: English
• Subjects: calorimetry; human metabolism; Kinesiology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2024.109842

The constrained energy model posits that the increased total daily energy expenditure (TDEE) in response to exercise is often less than the energy cost of the exercise prescribed. The mechanisms behind this phenomenon, coined “exercise-related energy compensation” (ExEC), are poorly understood, and it is unknown if ExEC is coupled with metabolic adaptation. Using a randomized controlled 24-week exercise intervention, individuals who demonstrated ExEC were identified. Changes to all components of TDEE and metabolic adaptation were assessed using doubly labeled water over 14 days and room calorimetry over 24-h 48% of individuals exhibited ExEC (−308 ± 158 kcals/day). There were no statistically significant differences in sex, age, or BMI between ExEC and non-ExEC. ExEC was associated with baseline TDEE (r = −0.50, p = 0.006). There were no statistically significant differences in metabolic adaptations for 24 h, sleep, or resting expenditures. These findings reveal that ExEC occurs independent of metabolic adaptation in sedentary components of EE. [Display omitted] •Half of participants exhibited ExEC following a 24-week exercise intervention•The degree of ExEC was related to baseline total daily energy expenditure•Metabolic adaptation was not evident in those with ExEC Kinesiology; Calorimetry; Human metabolism.