Aim: Assessment of the effects of moderate exercise on lipopolysaccharide (LPS)-triggered lung injury. Method: Thirty-two male Wistar rats were divided into four groups of eight as follows: (1) control; (2) LPS; (3) exercise (EX); and (4) exercise+ LPS (EX+LPS). Exercise groups were submitted to exercise (15 m/min for 30 min, 6 days/week, for a period of 8 weeks). LPS (1 mg/kg) was intraperitoneally injected on a daily basis for 5 successive days during the last week of the experiment. Ultimately, the levels of stress oxidative markers in the bronchoalveolar lavage fluid (BALF) and in lung tissues, total white blood cells (WBC) counts in the BALF, inflammatory markers in lung tissue, tracheal responsiveness to methacholine, and lung histopathological changes were assessed. Results: LPS injection increased the number of total WBC, neutrophils, eosinophils, monocytes, and lymphocytes as well as malondialdehyde (MDA) levels in the BALF, tumor necrosis factor-α (TNF-α), interleukin (IL)- 1β, and MDA in lung tissues, and tracheal responsiveness to methacholine, and caused lung pathological damages (P<0.05-P<0.001). Moderate exercise preconditioning decreased total WBC, neutrophils, eosinophils, monocytes, and lymphocytes counts in the BALF, diminished levels of TNF-α, IL-1β, and MDA in the lung, but increased thiol levels in lung tissues (P<0.05-P<0.01). Furthermore, moderate exercise alleviated tracheal hyper-responsiveness (P<0.01). Conclusion: Moderate training improved LPS-induced lung injury by attenuating lung inflammatory cytokine levels, oxidative damage, and pathological changes and tracheal hyper-responsiveness.