The purpose of the present study was to evaluate the effects of one session of aerobic exercise associated with low level laser therapy in lipolytic activity, lipid profile and inflammatory markers (C-reactive protein - CRP).

The adipose tissue is the main energetic reserve, being constituted by adipocytes, cells that accumulate lipids inside its cytoplasm, in the form of triglycerides.

Fat deposition can occur both in the subcutaneous compartment and in the visceral compartment and is the result of a positive energy balance in which there is an imbalance between the amount of calories consumed and the amount of calories expended. Thus, an excess of energy storage occurs in the form of triglycerides in adipose tissue, which results from a sedentary lifestyle and a diet based on lipid rich nutrients. When fat deposition occurs in abdominal adipose tissue may favor the development of metabolic disorders.

Recently the effectiveness of an innovative physiotherapeutic intervention - low power laser therapy (LLLT) - on adipose tissue has been studied. This therapeutic modality stimulates cytochrome C oxidase, causing the release of nitric oxide, increased mitochondrial membrane potential and adenosine triphosphate (ATP) synthesis and the transient increase of reactive oxygen species (ROS). It is proposed that ROS creates temporary pores in the adipocyte membrane, allowing the release of its lipid content. It is also suggested that a regulation of cAMP occurs, which stimulates the lipolytic cascade, converting the triglycerides to fatty acids and glycerol. In this way, low level laser therapy seems to aid in the reduction of adiposity and in the decrease of cholesterol and triglycerides serum levels . In addition, it assists in the reduction of the inflammatory process related to obesity, by reducing the pro-inflammatory cytokines.

The aerobic exercise, due to its low-moderate intensity, enhances the stimulation of lipolysis, by decreasing plasma insulin concentration and elevating the level of catecholamines. In this way, it influences the lipid metabolism, seeming to improve the lipid profile, through the degradation of the triglycerides as energetic substrate. In addition, the regular practice of physical exercise seems to promote a decrease in the inflammation state due to metabolic changes, through the reduction of pro-inflammatory cytokines, namely interleukin-6 and, consequently, C-reactive protein.

The application of low level laser therapy in the abdominal region enhances the release of fat acids and glycerol into the bloodstream, increasing the availability of the substrate for muscle energy consumption. However, if they are not used as energy, free circulating fat acids may bind to glycerol and potentiate, again, the accumulation of triglycerides in abdominal adipocytes. Thus, aerobic exercise seems to be a good option in the fight against this re-esterification, since it is expected that the resulting fat acids will be converted to acetyl-CoA, entering the Krebs cycle, being used as energy source during aerobic exercise.

Inclusion Criteria:

• age between 18 and 25 years.
• BMI between 18,5Kg/m2 and 29,9Kg/m2
• consider presenting abdominal fat

Exclusion Criteria:

• pregnant or intending to be in a period of 9 months
• participants with smoking habits
• participants with neoplasias, metabolic dysfunctions, renal pathologies, dermatological alterations
• participants with electronic devices
• participants with a condition that makes it impossible to practice physical exercise (disabling skeletal muscle pathologies and severe cardiorespiratory pathologies)
• participants under the effect of beta-blockers or other drugs which influence heart rate
• participants submitted to other fat reduce procedure