Research has confirmed that increased physical activity significantly enhances daily calorie expenditure without the body compensating by reducing energy use elsewhere. A study published on January 1, 2026, in the *Proceedings of the National Academy of Sciences* highlights how exercise contributes positively to overall energy output. Conducted by scientists at Virginia Tech in collaboration with the University of Aberdeen and Shenzhen University, the findings challenge long-standing beliefs about the body’s energy management.
Understanding Energy Expenditure
For years, a debate has persisted among researchers regarding how the body allocates energy. One theory posits a fixed energy budget, suggesting that increased physical activity leads the body to divert energy from other functions. Conversely, another theory proposes that energy expenditure is flexible, allowing for an overall increase as activity levels rise. The Virginia Tech study aims to clarify these competing ideas by measuring the total energy expenditure of individuals with varying levels of physical activity.
According to Kevin Davy, a professor in the Department of Human Nutrition, Foods, and Exercise and principal investigator of the study, “Our study found that more physical activity is associated with higher calorie burn, regardless of body composition, and that this increase is not balanced out by the body reducing energy spent elsewhere.”
Innovative Research Methods
The study involved 75 participants aged between 19 and 63, who represented a wide range of activity levels from sedentary to ultra-endurance athletes. Researchers utilized a novel approach to measure energy expenditure by having participants consume specialized forms of oxygen and hydrogen. Over a two-week period, participants provided urine samples, allowing scientists to estimate carbon dioxide production and, consequently, energy use.
Additionally, physical activity was monitored through a small waist-worn sensor that tracked movement in multiple directions. The results revealed a clear correlation between increased activity and higher total energy expenditure, indicating that essential bodily functions such as breathing, blood circulation, and temperature regulation maintained their energy demands even as physical activity levels rose.
This suggests that the body does not offset the calories burned through exercise. “Energy balance was a key piece of the study,” noted Kristen Howard, senior research associate at Virginia Tech and lead author of the article. “We looked at folks who were adequately fueled. It could be that apparent compensation under extreme conditions may reflect under-fueling.”
The research also found a strong link between higher activity levels and reduced time spent sitting, reinforcing the notion that individuals who engage in more physical movement tend to be less sedentary overall.
The implications of this study are significant. The findings indicate that the long-held belief that increased physical activity may not lead to a proportional increase in calorie burn could be inaccurate. While this study supports the additive energy model, the researchers acknowledge the need for further investigation to determine the specific conditions under which energy compensation might occur.
Overall, this comprehensive study sheds light on how exercise contributes to our daily energy budget, emphasizing the importance of staying active not just for fitness but also for overall energy management.