Effects of omega-3 supplementation and high intensity interval training in physical performance, blood pressure and body composition in overweight individuals

Background: High Intensity Interval Training (HIIT) has shown to increase oxidative capacity and maximum oxygen consumption (VO_2max) in different populations. On the other side, the consumption of Omega-3 fatty acids (O3) has positive effects on oxidative metabolism. Objective: To observe the effects of a combination of HIIT and O3 supplementation on parameters of physical performance, blood pressure, and body composition in overweight adults. Methods: 28 young, non-active, overweight individuals (22 ± 4 years; BMI = 25.8 ± 2.4 kg/m²) participated in the study. They were randomly assigned to four groups: an O3/HIIT (n = 7) which performed HIIT, 3 times per week, during six weeks and took 2 g of O3 supplement daily; a HIIT group (n = 7) whom performed HIIT protocol; an O3 group (n = 7) consumed 2 g of O3 supplement daily; and a control group (n = 7). VO_2max, maximum race speed, blood pressure, body fat percentage, and the sum of six skinfolds were measured at baseline and after the 6 week intervention. Results: Peak oxygen consumption increased more in the O3/HIIT group (+10.9%) when compared to the HIIT group, O3 group, and control group. Maximum race speed increased only the O3/HIIT group (+7.1%) and HIIT group (+11.9%). Systolic blood pressure decreased the most in the O3 group (-6.8%), compared to O3/HIIT, HIIT, and control. Lastly, fat percentage decreased in every group (-19.2% in O3/HIIT group, -20.2% in HIIT group, and -15.2% in O3 group), when compared to the control group. Conclusion: The results observed in VO_2peak in the O3/HIIT group, suggest an augmented effect when HIIT and O3 supplementation are combinedduring six weeks. Furthermore, fat percentage improved in all intervened groups when compared to control group.