It is generally accepted that an excellent path to shedding excess weight involves vigorous sports activities. Physical exertion undeniably offers numerous health benefits. Nevertheless, if the primary goal is waistline reduction, exercise alone might prove insufficient; dietary restrictions are also necessary. This conclusion was reached by evolutionary anthropologists at Duke University in the United States.
For an extended period, experts relied on a straightforward mathematical equation where calories burned from workouts were simply added to the basal energy expenditure. As noted in the journal Current Biology, a different framework, termed the constraint model, has emerged in recent years. This model posits that the human body possesses an inherent ceiling for energy expenditure that it endeavors to maintain without compromising its well-being.
Should an individual burn an excessive number of calories during a training session, the body initiates a compensatory mechanism. It dampens energy allocated to various internal functions, such as cellular repair, to keep the overall balance within a tight and predictable range. Consequently, the surplus calories incinerated at the gym only contribute marginally to weight loss.
The authors of the scientific study found that the constraint model offered a more accurate depiction of reality compared to the additive one. Researchers examined the outcomes of 14 distinct trials involving 450 participants, alongside data from animal studies. It was discovered that during aerobic exercise, the total daily energy expenditure rose by only about 30% of the anticipated increase.
This compensatory effect intensified when exercise was paired with dietary limitations. When energy output is high yet caloric intake from food is restricted, the body is compelled to draw upon stored fat reserves to sustain equilibrium. It is precisely under these conditions that weight reduction occurs most effectively.
Hence, physical activity does elevate energy expenditure, but to a lesser extent than commonly assumed. This clarifies why sports implemented without corresponding dietary changes often yield modest results in slimming down. Restricting one’s food intake plays an essential role by obligating the body to utilize its reserves rather than conserving energy in vital internal processes.
About the Author
