Background: Omega (ω)-3 fatty acids have positive effects on different body systems such as cardiovascular, respiratory, nervous, and skeletal systems. The purpose of this study was to examine the effect of ω-3 supplementation on pulmonary function in cadets participated in army ranger training.

Materials and Methods: In this study, 41 army cadets (mean age, 18.6±‌0.9 years) were randomly allocated to the supplement (S, n=21) and placebo (P, n=20) groups. The two groups participated in army classic military training 4-5 days/week for 8 consecutive weeks. The S and P groups were asked to consume 1000 mg/day ω-3 and placebo per day for 8 weeks, respectively. Pulmonary function was assessed at the first and end of the training.

Results: Results indicated a significant difference in FEV1, FVC, MVV, FEF25-75%, FIV1 at the end of the training compared to those obtained at the beginning in both groups however, the changes were markedly greater in the S group (P≤0.05).

Conclusion: It can be concluded that the supplementation of ω-3 (1000 mg/d) can induce positive alteration in different pulmonary function indices.