ABSTRACT Objective: To propose a duathlon model adapted for rats (associated swimming and running training) and compare it with the individual activities carried out separately, considering the glucose uptake and serum lactate production mechanism. Methods: Twenty-eight 90-day-old Wistar rats with a mean weight of 150-200 g were used. The animals were divided into four groups: control group, swimming group, running group, and swimming/running group. These animals were adapted to their respective training programs for three days and underwent the 4-week training protocol soon afterwards. Pre- and post-training blood lactate and blood glucose analyses were performed at the end of each week. Statistical difference was considered when the p value was less than 0.01 (p <0.01). Results: There was a decrease in glycemic levels and an increase in lactate levels in the swimming and swimming/running groups throughout the training period, which did not occur in the running group. Conclusion: The duathlon model adapted for rats proved satisfactory in terms of the production and stabilization of blood lactate levels. Level of evidence II; Therapeutic Studies - Investigating the Results of Treatment.