Acute effects of resistance exercise on energy expenditure: revisiting the impact of the training variables

Comprehension of the factors that affect energy balance is of key importance in understanding the regulation of body mass. Energy balance is determined, on the one hand, by energy consumption and, on the other, by energy expenditure. When these factors are not in equilibrium, it may result in an excessive accumulation or reduction of the energy stored endogenously as body fat. However, obesity is the most frequent result of the unbalance between food ingestion and energy expenditure. The number of overweight persons has been increasing in Brazil and in many other parts of the world. Recent results revealed that, among the population residing in Rio de Janeiro, 44% of men and 33% of women between 26 and 45 year of age were overweight or obese(1). Obesity, according to the World Health Organization(2), is considered a public health problem that leads to serious social, psychological and physical consequences, and is associated to greater risks of morbimortality by non-transmittable chronic diseases. Individuals with a body mass index equal to or above 30 kg.m-2 are classified as obese(2). Although the causes of this phenomenon are multifactorial(3) and therefore difficult to be established, the scientific community considers it wise to investigate ways to increase daily energy expenditure in order to reduce or control the prevalence of obesity. Energy expenditure of physical activity is the most variable component of total energy expenditure. It can be voluntarily increased, contributing to a negative energy balance when food intake is also controlled(4). Programs combining energy restriction and aerobic exercises have been, for a long time, indicated for weight loss(5,6). This is justified by the role of physical activity in Acute effects of resistance exercise on energy expenditure: revisiting the impact of the training variables