Purpose: This study evaluated the effect of aspartate (ASP) and asparagine (ASG) supplementation on fatigue determinants in Wistar rats exercised to exhaustion by swimming. Methods: The animals were tested for anaerobic threshold (AT) determination and then supplemented with 350 mM ASP + 400 mM ASG · day⁻¹ (AA group, n = 16) or 2 ml · day⁻¹ of distillated water (PLC group, n = 16) for 7 days. On the 7th day of supplementation, the animals were divided into 4 new groups and killed at rest (RAA, n = 8; RPLC, n = 8), or immediately after the swimming exercise to exhaustion (EAA, n = 8; EPLC, n = 8). Results: No significant differences were observed between amino acids and placebo rest groups for muscle and liver glycogen, blood glucose, lactate, ala-nine, and glutamine concentrations. However, in the exhaustion groups, the EAA group showed higher exercise time (68.37+ 25.42 X 41.12 + 13.82 min, p < .05) and lower blood lactate concentration (8.57 ± 1.92 X 11.28 + 2.61 mmol · L⁻¹, p < .05) than the EPLC group. Moreover, the ASP+ASG supplementation decreased the rate of glycogen degradation of gastrocnemius (1.00 + 0.51 X 3.43 ± 0.99 μg · 100 mg of tissue sample⁻¹ · min⁻¹), extensor digitorius longus (5.70 ± 2.35 X 8.11 ± 3.97 μg · 100 mg of tissue sample⁻¹ min⁻¹) and liver (0.51 ± 0.34 X 3.37 ± 2.31 μg · 100 mg of tissue sample⁻¹ min⁻¹) for EAA. Conclusion: These results suggest that ASP+ASG supplementation may increase the contribution of oxidative metabolism in energy production and delay fatigue during exercise performed above the AT.