Objective: To evaluate the effect of Shin-I essential oil inhalation on blood lactate changes in rats subjected to treadmill exercise.Methods: Adult male Sprague Dawley rats (n=12) were randomly divided into the control or the Shin-I group. Rats were subjected to a treadmill exercise program (15 m/min for 30 min). After exercise, rats were exposed to 200 μL of water or Shin-I essential oil, respectively, using a nebulizer for 180 min during the recovery period. Blood samples were collected every 15 min. Blood glucose and lactate concentrations were determined in a CMA 600 analyzer.Results: The basal glucose and lactate levels were no significantly different between two groups. After exercise, glucose levels were slightly increased to about 110%-120% of the basal level in both groups. Lactate levels of both groups reached to 110%-140% of basal levels during exercise. In the recovery period, lactate levels further increased to 180% of the basal level and were maintained at a plateau in the control group. However, lactate levels gradually decreased to 60%-65% of the basal level in the Shin-I group. Lactate clearance was significantly enhanced after Shin-I essential oil inhalation.Conclusions: Our results provide evidence that Shin-I essential oil inhalation may accelerate recovery after exercise in rats.