Acute Effect of Aged Garlic Extract and High-Intensity Interval Exercise on Metabolic Rate, Substrate Oxidation and Salivary Cortisol in Inactive Women

Background and purpose: Nowadays, the use of traditional herbal remedies along with exercise has become very popular for the prevention and treatment of diseases. The aim of this study was to investigate acute effect of aged garlic extract on metabolic rate, substrate oxidation, and salivary cortisol during and after high-intensity interval exercise (HIIE) in inactive women. Materials and methods: The study population included ten inactive women in Birjand (age 24±6 years, BMI 22-23 kg/m2). Individuals participated in two separate sessions (one week apart). In the first session, aged garlic supplements (600 mg) were taken one hour before HIIE. In the second session, the placebo (600 mg of starch) was taken. The HIIE program consisted of 11 alternates (1-minute with 90% vVO2max followed by 2-minute rest intervals with 60% vVO2max). Pre, during, and after HIIE, oxygen consumption and carbon dioxide excretion were measured using the respiratory gas analyzer in order to calculate metabolic rate (Energy Expenditure, VO2) and substrate oxidation (Fat Oxidation, Respiratory Exchange Ratio (RER)). Salivary cortisol was measured using chemiluminescence method. Repeated analysis of variance was applied for statistical analysis of the data. Results: The results revealed that there was no significant difference in VO2 (P=0.28), Fat Oxidation (P=0.09), RER (P=0.083), and energy expenditure (P=0.76) between aged garlic and placebo intake. There was no significant difference in salivary cortisol (P= 0.66) either. Conclusion: Generally, aged garlic supplement intake along with HIIE does not have any effect on metabolic rate, substrate oxidation, and cortisol level in inactive women.